Holle Moms-to-be, it’s very easy to calculate your pregnancy Due Date. If you have missed your periods, then you must be knowing your last month’s period date is also called as LMP. So, pregnancy due date can be estimated with the help of this Calculator.

Last menstrual period date and period length are commonly used for confirming pregnancy due date and pregnancy weeks to calculate. 

I have given an example for you on how to calculate your last month’s period to confirm your pregnancy week.

Below I have also shared a video on How to Calculate Your Pregnancy by Weeks, Months & Trimesters.  And Pregnancy week by month chart to download. 

For Example if 1st December 2019 was your first day of last month period. You both involved in lovemaking in December and in the month of January you missed your period.

And your pregnancy gets confirmed in January  2020 that you’re pregnant. So, as per pregnancy rules, the First day of LMP date counts as Zero Week Pregnant.  1st December 2019 is counted has first-week pregnancy as per you but you’re in your zero week pregnancy. So, here you’re in your zero weeks.

So, as per pregnancy rules, you will be one week pregnant during your second week. It’s all that you have to put one week behind you and start the count from another week.

  • In your first week you are – zero week’s pregnant
  • In your second week you are – one week pregnant
  • In your third week you are – two weeks pregnant
  • In your fourth week you are – three weeks pregnant
  • In your fifth week you are – four weeks pregnant, here is where your pregnant gets confirmed.

So, you’re in First-month pregnancy which is called as 1st Trimester. The given trimester’s chart is going to help you understand weeks into months.  You can find out your pregnancy weeks and estimated due date by using Your YouTube Mom pregnancy calculator accurately. I have also shared 

Watch the video to Understand: This video is also going to help you calculate whether you know your LMP date or if your periods are irregular. To know more click on the video. Don’t forget to give this video a special LIKE, SHARE & SHARE it with your friends!!

How to Calculate Pregnancy Weeks and Months?


Pregnancy week by month chart to understand the 3 trimesters of pregnancy 

First Trimester Weeks (1st Trimester)

  • 01-04 weeks: First month of pregnancy (1 month)
  • 05-08 weeks: Second month of pregnancy (2 months)
  • 09-13 weeks: Third month of pregnancy (3 months)

Second Trimester Weeks (2nd Trimester)

  •  14-17 weeks: Fourth month of pregnancy (4 months)
  • 18-21 weeks: Fifth month of pregnancy (5 months)
  • 22-26 weeks: Sixth month of pregnancy (6 months)

 Third Trimester Weeks (3rd Trimester)

  • 27-30 weeks: Seventh month of pregnancy (7 months)
  • 31-35 weeks: Eighth month of pregnancy (8 months)
  • 36-40 weeks: Ninth month of pregnancy (9 months)

Pregnancy week by month chart to understand the 3 trimesters of pregnancy

How to calculate pregnancy weeks By Shweta Sharma