How long do you ovulate after a positive ovulation test

So you want to get pregnant. Like, now. You’ve heard a lot of women have had success with Ovulation Predictor Kits (OPKs), which test for a surge in Luteinizing Hormone (LH), so you’re interested in stocking up on those. The only problem is you’re not quite sure what LH is, how OPKs work, or whether your surge is different from another woman’s. And, of course, you need to know everything. Like, now. We’ve got answers. Let’s begin!

What is LH?

Your brain is pretty smart, right? I’d say genius – did you know your anterior pituitary gland, which produces your reproductive hormones, the masterminds of your fertility, is located in your brain? That’s right, hormones produced in your brain play a leading role in releasing a single egg from an ovary in your uterus and helping you achieve pregnancy.

The hormone responsible for triggering your ovary to release an egg, and ovulate, is Luteinizing Hormone, or LH. After a dominant egg has grown large enough for ovulation and your body has produced a large amount of estrogen, LH production, which is low throughout your cycle, ramps up and up over a period of days until it ‘peaks’ or ‘spikes,’ signaling for your body to release the dominant egg in hopes of achieving pregnancy.

How do I know when LH peaks?

LH is a very popular hormone among women – but not only because it signals the beginning of ovulation. It’s also a superstar because it can be detected and measured through urine, giving women the power to know when they will ovulate – at home and at a reasonable price. How? With Ovulation Predictor Kits (OPKs).

What are OPKs?

OPKs are strips (very similar in appearance to pregnancy tests) that contain a substance that turns red if an LH threshold, or high enough LH concentration, is met. Like pregnancy tests, either one or two lines will turn red – the ‘control,’ to know the test is working, will always turn red (look closely on the test to see the control line indicated), and the LH test line will only turn red if your LH is ‘peaking.’

LH Surge: When to Detect Peak Fertility with an OPK

How soon after an LH ‘peak’ will I ovulate?

Ah, the million-dollar question! The simple answer is – it depends. On you. Every woman and her reproductive system is wonderfully unique, so there is no one size fits all timeframe here.

With that said, ovulation occurs ~36-40 hours after the LH surge is released from the brain. But the surge that patients detect in urine occurs ~24-36 hours before ovulation actually happens.

How long does the LH surge last?

Another brilliant question!

An LH surge for most women lasts between 1-3 days, with an upswing toward the surge and a downslope to return to normal baseline levels. So the peak of the surge is shorter, but the entire ‘surge process,’ from start to finish, is generally between 1-2 days.

I see a pink LH line – am I surging?

Because your body releases more and more LH (usually in the morning hours) before the highest peak, you could see a very faint LH line taken on cycle day 12, for example, become a pink line on another OPK (each ‘kit’ is one test strip) on day 13, and then a bright red line on day 14, followed by a light pink line on day 15, and no line at all on day 16 (which may be the day you actually ovulate, because LH is indicative of impending ovulation, not ovulation itself). This ‘curve’ was your LH surge – up, up, peak, down, down.

But – this curve moves much faster for some women, who could have a pink line in the morning and a bright red line that evening.

So how often should I be testing?

You should be testing once daily, although most women closely tracking their ovulation and LH patterns will track multiple times a day on the day of an expected surge (after a faint or light pink line indicating the upcoming surge or bright red line) to know exactly when they are peaking.

In order to track correctly, it’s crucial to understand your cycle length and usual ovulation day. After tracking your cycle for a few months, you’ll know how long it is (the number of days between the start of one period and the start of the next period). Most women ovulate smack dab in the middle of their cycle, and they can tell because of the type of cervical discharge they have – clear, ‘egg white’ discharge usually accompanies ovulation.

So when should I start testing every month?

So let’s say you have a 28-day cycle, and you know from previous OPKs and discharge (and maybe even taking your temperature!) that you ovulate on day 14 of a normal cycle (stress and other factors can lengthen the duration of your cycle and delay ovulation so keep this in mind if you’re not seeing an LH surge when you expect to).

In this scenario, you should take a daily OPK starting day 10 and continue until you see an LH surge (if your ovulation is late, you’d miss it if you stopped testing on day 14, when you expected to ovulate). Women with 24-day cycles who ovulate on days 10-11 should start testing on day 6 until they surge.

Most women do not ovulate smack dab in the middle of their cycle, though. Only ~13% of women have a 28-day cycle. Therefore, lots of patients get the timing wrong on when to test, as the surge can and does happen either earlier or later than expected based on a 28-day cycle.

Using a period tracking app like the one built into iPhone iOS is a great way to get an accurate day of ovulation.

I want to test often, but aren’t OPKs expensive?

Not all of them! If you purchase brand-name OPKs from the pharmacy, getting many so you can test several times per cycle will get very expensive. But if you look around the aisle, you’ll see more generic tests offered in bulk that works just as well. Women looking to get even more tests in bulk can look online, where hundreds of working tests can be purchased for a steal.

When is the best time of day to test?

The best time to check LH is late morning through early evening. The LH surge is often released from the brain in the early morning, so if you get up early and test your first-morning urine, you could miss it. In addition, you should decrease fluid intake for ~2 hours prior to ensure that your urine isn’t too diluted.

What if I never see a surge? When should I see a fertility specialist?

If you never see a surge, don’t panic. It’s possible your ovulation is delayed due to stress, so your LH peak is late, too. In this case, test for several additional days. Another possibility is that your surge is not meeting the specific LH volume threshold on the OPKs – but this does not mean you are not surging or not ovulating!

In this case, you may want to look into low threshold OPKs or go to a fertility doctor or reproductive endocrinologist, who can draw your blood to see when you peak (LH is more accurately measured through blood than urine) and ovulate.

If you really don’t think you are ovulating because you never peak or are getting all sorts of wonky OPK results (like many peaks days apart or a peak every day), you should consider seeing a fertility doctor, too – he or she will run bloodwork to see what’s going on and if necessary, prescribe effective treatment to induce ovulation or achieve pregnancy.

Furthermore, if you are a woman with irregular periods, or you know you have PCOS (polycystic ovary syndrome), you are likely to have a difficult time with LH kits and should see a reproductive endocrinologist sooner rather than later.

Can I have two LH surges?

While this is rare, some studies suggest it is possible to have two (or more!) LH peaks, and yes, ovulate more than once at two separate times in your cycle.

However, the vast majority of fertility doctors and OBGYNs believe that each cycle allows for one LH surge and one instance of ovulation, and most women who have tested LH every day of their cycle would agree!

If you are seeing two surges, it might be because your system is under a type of transition, such as with breastfeeding mothers just resuming regular ovulation.

OK, I saw an LH surge. Now what?

Yay! OK, now some more math – since we know ovulation happens 12-48 hours after a positive OPK, an ovulated egg lives from 12-24 hours, and sperm lives for as long as five days, we can say you should definitely have sex as soon as you see an LH peak and for up to three days afterward. But you can also have sex the five days leading up to ovulation and then the day after ovulation, too.

Overwhelmed? Don’t worry – once you start tracking, it becomes second nature!

Why am I seeing an LH peak during pregnancy?

If you took an OPK when your period was a few days late, and it showed two red lines or a surge, congratulations, you are likely pregnant!

Why? Fascinatingly, the pregnancy hormone, Human Chorionic Gonadotropin, or hCG, and LH share a similar protein structure, so a pregnant woman who takes an OPK would test positive – but it’s not because she is about to ovulate, it’s because she is pregnant.

And if you’re wondering, no, it won’t work the other way; a woman experiencing an LH surge will not get a positive pregnancy test result. That’s because hCG is the same protein structure as LH, plus a few other proteins. Cool, right?

So, OPKs are a good idea?

They are a great idea! While they are not everyone’s cup of tea, when paired with knowledge about your menstrual cycle and your cervical discharge, they are an excellent – and for most women, indispensable – tool to achieve pregnancy.

It is advised by The American College of Obstetrics and Gynecology that if you are 35 or older and have been trying for six months to get pregnant without birth control, it is recommended to see a fertility specialist.

While OPKs are a great tool to know more about your menstrual cycle, time may be of the essence, and you may want to seek the help of a reproductive endocrinologist sooner than you may think, depending on your age.

How do you get pregnant after a positive ovulation test?

Can you ovulate the same day as a positive ovulation test?