why does it say i am in my fifth month when i am 20 weeks?

Question

doesn't that mean i am in my sixth month? 4x5=20. i know that you're really pregnant for more like 9 and a half to 10 months...are they just averaging that in and trying to make it only 9 months for us? very confused. at 20 weeks i can see saying i AM 5 months pregnant, but aren't i IN my sixth month???

lol, i'm still confused. i can see i need to go one more week to in my sixth month (damnit! lol). but like the books say month sixth is 23-27 weeks....how does that work???

Answer 1

This has confused pregnant women for eons.

The day you miss your period you are, gestationally, two weeks pregnant, however, they go by the date of your last menstrual period (LMP) which makes you four weeks pregnant. Therefore, the day you miss your period you are already a month pregnant. So for the sake of clarity, let's say your last menstrual period started January 1st of this year:

Month 1: Jan 1 - Jan 29th
Month 2: Jan 30th - Feb 26th
Month 3: Feb 27th - March 26th

and so on. So with a 14 day cycle you got pregnant on January 14th, however, on February 27th you have only been physically pregnant for a little over six weeks, however you are already starting your third month. Clear as mud, huh? My rule is let the pregnant woman claim to be as pregnant as she wants to be :)

Answer 2

yeah, it is a bit confusing

start w the easy part. You've got 52.2 weeks in a year, and 12 months. So on average, a month is 4.35 weeks.

So 1 month is 4.25 weeks, 2 months are 8.7 weeks, 3 months 13.0 weeks, 4 months 17.4 weeks, 5 months 21.7 weeks (not 20), 6 months 26.1 weeks, 7 months 30.4 weeks, 8 months 34.8 weeks, and 9 months 39.1 weeks.

So at 20 weeks you are definitely in your 5th month but you need 1.7 more weeks to have completed 5 months, and thus enter the 6th.

Now where it gets vicious, is that the term normally used (9 months / 40 weeks) is just an average. Very few serious research has been undertaken to measure the actual duration of the pregnancy. One of these, realised by Harvard School of Medicine, has found 274 days (from ovulation) for first-time mothers, and 269 days for others.

The classical rule is "Naegele's rule", i.e. 1st day of last period, +10 days, minus 3 months. This corresponds to 274 days or 39.1 weeks. Well, in Europe it is mostly used with +10 days. But in the US it is mostly used with +7 days, giving you 271 days from 1st day of last period.

Other sources have from 266 yo 270 days from conception, so if this happens at time of ovulation at mid-cycle, add 14 days, you get 280 to 284 days from 1st day of last period.


Bottom-line: this is very confusing, there is no one rule, it varies by geography, and the usual 40 weeks and/or 9 months (which are not the same thing in terms of number of days) are good enough, given that, close to the end, other factors will play a role.

We have 4 kids and I have tried to make any sense of all this, and indeed found out that you couldn't.

Which doesn't in any way reduce the joy generated by the birth of a child, or reduce in any way the mother's impatience to see the baby she has been carrying! ;-)

Good luck

Answer 3

There are 4 wks for every month. 21 weeks puts you at the start of your sixth month. Like you said 4x5=20, 4x6=24

Answer 4

When you reach 21 weeks then you are in your 6th month. The first four weeks is a month then week 5,6,7,and 8 is two months then 9,10,11,and 12 is the third month then 13,14,15,and 16 is the 4th month then finally 17,18,19,and 20 is the 5th. So the 21st,22nd,23rd,and the 24th is the 6th month. And pregnancies do last 10 months. I was 10 months and 2 days when I gave birth to my child just a month and a half ago.

Answer 5

I know how you feel! Why didn't they make months exactly 4 weeks? Would of made it alot easier lol. I'm 25 weeks and I can't say if I'm 5 or 6 months pregnant! Guess I'll just stick to weeks

Answer 6

I know that it can be very confusing alot of the time. I never went by weeks, b/c that confused me even more. I always went bo months, b/c it is less confusing. They say you are in your fifth month b/c they count the month that you concieved as already being pregnent one month. We are actually pregnent for 10 lunar months., but I have never really understood that either. If I was you I would count how many months until your baby is due, then see how many more months from now till your the month of your due date. I hope that my advice has been helpful.

Answer 7

4 weeks times 5(mo)= 5 months pregnant or in your fifth month, if your between 20-23 wks.
go week by week, its easier to follow.

Answer 8

you are working on the theory that every month has exactly 4 weeks but they dont i can see what you are saying but if you worked it out by a callender you would prob be in your 5th month hope i have helped. could you please have a look at my question in the pregnancy section titled help!!!! im 16 and might be pregnant!!!! thanks

Answer 9

because they go by lunar months, not calendar months. a lunar month is 28 days or 4 weeks.