Will O Late Make AF Late?

foxfire_ga79 · #1 March 30th, 2009, 08:04 AM

Good morning ladies!
I was wondering since I'm O-ing about a week late, if I don't get pregnant should I expect AF to be a week later than normal too?
And would O-ing late change my due date if I get pregnant, or does it always just go from CD 1?
Thanks!

MamaAnna · #2 March 30th, 2009, 09:16 AM

There are two ways to figure your due date. One is going by the first day of your LMP. That is the most common since most women know it. However, if you know your O date you can calculate it based on that and it will give you a different due date. Of course the first measurements would give you the best idea, but it's great to have a date before then!

O'ing late can make AF come late, but by how much isn't certain. AF may still show up on time and you'd have a short LP that cycle. On the other hand your LP could just be off by a day or two. Your chart will be the best indicator, especially if you experience a big temp drop around the time AF is due to arrive. Here's hoping for a bean though!

MountainMomma · #3 March 30th, 2009, 10:50 AM

Yes, for the majority of people, if you ovulate later than normal your period will be late by that much too. The luteal phase of your cycle is typically supposed to be the same length (give or take a day) each month. Typically your doctor would still just use the first day of your last menstrual period to figure your due date up until the first ultrasound at which point SOME doctors might change your due date based on the dating process of that first ultrasound.

Niamh ૐ · #4 March 30th, 2009, 03:46 PM

Unless you're pregnant, or you have a condition that is causing short luteal phases, you should start your period 12-16 days after you ovulate. So yes, a late ovulation will probably make a later period (unless your luteal phase is shorter than normal).

Your doctors will always initially calculate your due date from your LMP, but the due date can change by measuring the fetus via ultrasound. However, calculating your EDD based on when you *actually* ovulated is much more accurate than calculating it based on LMP.

foxfire_ga79 · #5 March 30th, 2009, 08:55 PM

Thanks!
It's going to be tough knowing AF is likely to be late either way now because of this.
An EDD calculated by LMP would be 12-16, but calculated by O puts it closer to 12-19/20. So last month I had my hopes up for a Thanks Giving turkey and now I'm hoping real hard for a Christmas present!
I'll save and then post a pic of my chart tomorrow morning after I enter in my temp. A few days ago last week my temps were near 97. I had a temp I discarded day before yesterday because I woke up an hour and a half late. But yesterday my temp dropped to 96.5 and then today shot up to 97.42. I hope it's up again tomorrow.
Now, if I'm pregnant my temp will stay up but if I'm not pregnant it will drop again in a few days?

Sorry for so many questions! I used rhythm method off and on for 10 years, but I've never actually charted. lol All this is so new and confusing to try and learn all at once.

MamaAnna · #6 March 31st, 2009, 04:06 AM

It's hard to say what your temp will do if you're pregnant. My BFP didn't look any different until the day AF was due. Normally it would plummet, but that day it stayed up. I tested and got my BFP. Some women do experience a noticeable thermal shift when implantation occurs though. The best tell will really be if your temp stays up or goes up when AF is due since it isn't an exact science.