How To Count Your Pregnancy In Weeks And Months

by | May 4, 2018

How do I count my pregnancy in weeks and months?

There is no way to know exactly to the day when you ovulated and conceived, so as a result, most health professionals will date your pregnancy based on your last menstrual period instead. To learn how to count your pregnancy in weeks and months using this method, you first have to remember when your last period started. The first day of your last period counts as day one of your pregnancy. Some women prefer to count their pregnancy from the date they were likely to have ovulated during the month they conceived. This date will usually be about two weeks after the date of your last menstrual period, so you may find health professionals telling you that you have been pregnant for two weeks longer than you really have been.


What if I don’t know the date of my last period, or have irregular periods?

The calculations that health professionals use works best if you have regular periods every 28 days. If you don’t know the date of your last period, or if you have an irregular cycle, it can be a little more difficult to determine and give you an accurate due date. The first time you go for an ultrasound, which is called your dating scan, the sonographer will measure your baby from head to bottom and will be able to give you a more accurate idea of how far along in your pregnancy you are. You should be offered a dating scan by your doctor when you’re between 10-13 weeks plus six days pregnant, based off of your last period.


How am I five weeks pregnant, if I’m in my sixth week of pregnancy?

A simple way of explaining how to count your pregnancy in weeks and months is by thinking about age. When your baby turns one year old, they have finished their first year of being alive, so this means they will be 1 year old during their second year of life. So, this means that when you complete your first week of being pregnant, you’re still only one week pregnant until you finish the second week. Example: in your first week of pregnancy, you are zero weeks pregnant. In your second week of pregnancy, you are one week pregnant, and so on.


What is a trimester?

A trimester means three months since most pregnancies are around 9 calendar months long, your pregnancy will be divided into three trimesters. They are used as a way to describe the changes that are happening in your body.

  • Your first trimester starts at the beginning of your pregnancy, and lasts until your 13 weeks and six days pregnant. Along with the excitement of expecting your new baby, you may also feel nauseous and exhausted.
  • The second trimester is from weeks 14 through to 27 weeks and six days. During this period, you may start to feel better and less nauseous. Your bump may start to show and the symptoms of early pregnancy will be behind you.
  • Your third trimester starts at 28 weeks and lasts until your baby is born. Your baby will have a growth spurt during this time so you are likely to feel exhausted once again.
  • You might hear people talking about the fourth trimester, and they are referring to the first three months of your babies life when you are bonding.


So there you have it. A simple guide on how to count your pregnancy in weeks and months.

How did you count your pregnancy? Let us know in the comments section below!


Alex Jones

Associate Editor, USA | Contactable via [email protected]



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