Question about how far along I am?

Question

Okay i'm confused. Why do they count how far along you are by the date of your last period?

If you go by the date of my last period that would make me: 24 weeks and 2 days.

If you go by the date I believe we conceived it would make me: 22 weeks and 5 days.

Which is right? Do you count from your last period or the day you believe you conceived?

I had thought I conceived during spring break here. But now I can't remember if that would've been the 17th or 18th or the 24th or 25th.

When I do my ovulation calculator - it states I should've been most fertile between the 13 and 18th.

Ack! This is all irritating me now. I thought I knew when I conceived but now i'm not sure. I don't know why it's so important to me to know the day I conceived but it is! And now it's been so long I can't remember what other days it could've been on! lol....

Answer 1

They go by LMP because so many woman don't know when they ovulated.  Unless you are 100% sure of ovulation date (which isn't always day 14) then you can't be sure of when you got pregnant. Conception is the date the egg and sperm meet not necessarily the day you had s*x.  Sperm can survive sometimes 5 days in your body before meeting the egg (that happened to me this time around) so LMP gives them a better way for estimated due date, many Dr's now will also do an ultrasound before 12 weeks to confirm a due date too.  

Answer 2

They go by your last period, because when your period starts you are technically 1 weeks pregnant then. My LMP would make me 4-5 weeks further then I am. I had iregular cycles, that lasted about 35-45 days so I ovulated late. Unless you know when you ovulate and your period is extremly regular, you may of mis calculated when you ovulated. You cannot go based on the online calculator they are estimators depending on what information you put it.

I had to have a transvaginal ultrasound to date my pregnancy in the begining, and I have just counted since then.

Answer 3

They always calculate based on the LMP because most women do not know exactly when they ovulated or conceived. The due date is exactly 40 weeks from the LMP date, or using Nagele's rule, you add 7 days and count back 3 months from your LMP date to find your due date.

It doesn't really make much difference, because due dates are estimates only and you are considered "full term" at 37 weeks, and not formally "over due" until about 41-42 weeks.

Answer 4

Doctors go by your last menstrual period.

Answer 5

you go by the date of your last period.

since most people dont know when they concieved doctors always go by the first day of your last period.

its almost impossible to know the day you 'concieved' since sperm can last for up to 5 days.

congrats and very cute baby bump  :]

Answer 6

you are right this is probably a well know question, I'm currently pregnant and i asked the same question.....

you go from the 1st day of ur last period.....

my 1st day of my last was 19th may therefore I'm 14wks

hope this helps!

and god luck with your baby xx

Answer 7

Your body NEVER goes along with what should be... they take the date of your last period and baisically you concieved two weeks before that...sooo really you could be anywhere from 24 to 26, if Im even going by the right calculations.