Which way of counting preg weeks?

[PrayinFor12]

I've found 2 different ways to count how many weeks pregnant we are.

First, there's the "count from the first day of your last period" method. But that puts you 2 weeks more pregnant than you really are!

Second, there's the "count from the day you ovulated" method.

So, if you ovulated 21 days ago, are you 3 or 5 weeks pregnant?

Which counting method is the standard one? I don't know what to tell people!

[Pyrodjm]

The standard way seems to be to count from your last period. If you ovulated late in the cycle, like I did you add 14 days to your O date.

[Rivka5]

The standard way is to count from the first day of your last period. However, in The Pregnancy Book Dr. Sears does it the other way. It's soooo annoying to have to convert back and forth in your head all the time, if you're using his book.

[PrayinFor12]

So you do count the 2 weeks before you're actually pregnant! It's like an acceptable big fat lie. Hilarious!

So, anybody know why that is? Maybe because that's when that particular egg starts maturing?

[hookahgirl]

Because not every woman O's on the same day or implants on the same day PO, so its a Dr's way of rounding up!
Whit