How far along are you after missed period

If you were having regular periods before pregnancy, your doctor will calculate your due date based off of your last menstrual period. This goes back to the fact that in order to get pregnant, your body ovulated—or released an egg—roughly in the middle of your cycle and it was fertilized by sperm. That was the moment of conception.

By the time most women miss a period and find out they’re pregnant, the baby has been growing for 2 weeks, but the mother is actually 4 weeks along because the gestational period starts with the first day of your last period.

To clarify, the gestational period of 40 weeks actually starts with the first day of your last period, which adds two weeks of time to the gestational period when your baby didn’t even exist yet…clear as mud, right?

Is an ultrasound a more accurate way of finding out my due date?

If you are having irregular cycles before getting pregnant, an ultrasound is usually done to find out how far along you are. An ultrasound is actually the most accurate way to date a pregnancy because all fetuses grow at a consistent rate during the first trimester and early second.

In other words, if your baby measures 9 weeks 2 days when you have your ultrasound, that’s how far along you are, no matter when your last period was.

Some women with regular cycles are confused about why their ultrasound due date doesn’t match up with their last menstrual period due date. Ovulation isn’t a perfect science and can happen earlier or later than the norm, which might shift your due date slightly.

That’s okay…a few days or even a week of discrepancy won’t change your dates. Your doctor will go with the due date obtained from your ultrasound.

What happens if my baby is measuring big or small later on? Does my due date need to change or will I deliver early?

You’ll notice at every prenatal appointment after 20 weeks, your doctor will measure your belly. That measurement should match your gestational age in centimeters. If you are measuring smaller or larger than what you should be, then the doctor might order an ultrasound. This will tell them if the discrepancy is due to the actual size of the baby, the amount of fluid surrounding the baby, or maybe just the way you’re carrying the baby.

If the baby is actually smaller or larger than what they should be, underlying issues need to be considered that might be causing the discrepancy in growth. For example, mothers with uncontrolled diabetes (Type 1, Type 2, or Gestational) cook very large babies. When a baby is small, it might be due to a placenta that’s not working like it should.

These discrepancies might affect delivery, but they might not. For example, if your baby is consistently measuring small and falling below where they should be, your doctor might decide you need to be delivered because your baby would be better out than in.

If your baby is extra big and you’re measuring 40 weeks at 37 weeks, your body might think it’s done and go into labor early….or you might go to your due date and things will go as planned. If you have questions about your due date, talk with your doctor who can give you the best information.

4 Weeks Pregnant: The 4th Week of Your Pregnancy

Congratulations! Pregnancy weeks four through seven are when most women discover they are pregnant. This week-by-week newsletter will keep you informed about what to expect during your pregnancy. If you have just found out that you are pregnant, you may want to begin by reading weeks 1 through 3.

How is pregnancy calculated?

There can be a lot of confusion when discussing the way in which pregnancy is calculated. Since most women do not know when they conceived as it is challenging to know exactly when ovulation occurred, pregnancy is calculated from the first day of your last menstrual period (LMP). Counting from your LMP, your pregnancy will last around 40 weeks. For more information on how pregnancy is measured, please see our information on calculating your dates.

What changes are occurring in your body when you are 4 weeks pregnant?

You may begin to exhibit some early pregnancy symptoms such as breast tenderness, headaches, lower backaches, and nausea. It is important to know that many early pregnancy symptoms are similar to those you may experience before your period. Other women may not have any pregnancy symptoms except for a late or irregular period. If you have missed your period, then you could take a pregnancy test. This would be the earliest that a home pregnancy test can detect pregnancy.*

What is happening with your baby when you are 4 weeks pregnant?

There are three layers to your baby- the ectoderm, mesoderm, and endoderm. These three layers will form the baby’s organs and tissues. The ectoderm will become the nervous system (including the brain), skin, hair, nails, mammary glands, sweat glands, and enamel for the teeth. The mesoderm will become the heart, circulatory system, skeleton, connective tissues, blood system, urogenital system, and the muscles. The endoderm will house the lungs and develops into the lining of the gastrointestinal tract, the liver, pancreas, and thyroid. Arm and leg buds begin developing at this point, although they are not clearly distinguishable. The placenta has also begun to form and is producing some important hormones including hCG. There is a movement of rudimentary blood through the main vessels.*

How big is your baby?

Babies are still very small at this point and measure about 0.078 inches (1.98 millimeters) in length.*

What should you plan for this week?

If your period is late or if you have an irregular period, you may want to take a home pregnancy test. If the result is positive, you can try to schedule an appointment with a health care provider, although many health care providers wait to see you until you are 8 to 12 weeks pregnant. If your test is negative and your period is late, then you should wait a week before testing again. Some women take 2 to 3 weeks after a missed period before producing a detectable level of the pregnancy hormone. You also want to begin looking for a health-care provider and decide where you will have your baby. Many doctors and midwives will allow you to arrange an appointment so you can meet them and ask questions before deciding if they will become your provider. For more information on choosing your health care provider, see our information on your birthing choices.

Tips for making your pregnancy better

If you have not begun an exercise routine, check with your healthcare provider to see what he/she recommends. Even if you already have a routine, you might want to read about exercise during pregnancy. Take a look at our information on:

• Exercise guidelines during pregnancy 
• Effects of exercise during pregnancy
• Top recommended exercises
• Exercise warning signs

You also want to be careful about the different medications you take during pregnancy. You should check with your health care provider before taking any over-the-counter or prescription medications. Your prenatal vitamin should contain at least .4 mg (400 micrograms) of folic acid. Prenatal vitamins normally contain .8 mg to 1 mg ( 800 micrograms to 1 milligram) of folic acid and also have high iron content. These are important for both you and your baby.

Tips for mom’s partner

Continue being open with your partner about your fears and excitement about her being pregnant. Talk about when you want to share the news with family and friends. Think of creative ways to share the news with friends and family. A happy mom is a happy baby. The most important thing you can do and assure mom feels happy and stress-free throughout her pregnancy.

How far along are you when you miss?

How long after missed period is due date?