Please help!

[HHOB]

I'm 27 weeks along and have been having terrible anxiety.
On August 11 2012 I ended up sleeping with a friend of mine.. We didnt finish, because i
Snapped out of it, and realized what i was doing Problem was I had
A boyfriend at the time, we slept together the next night, and a few more times
Through out the week.. Now my due date is May 12, 2013, which was established at my 18
Week ultrasound..  I've figured out that my
Conception date should have been August 19th.. So should I still be worrying? Or could
It be that I feel so guilty for what I've done that I am driving myself mad. I don't know, no need of bashing me either I would just love an honest awnser

[AnnieBrooke]

That ultrasound then gave you an implicit first day of last period of October 7 -- you might check my work on that, I'm just counting on a calendar.  Anyway, sounds like you ovulated at least as late as August 19, and maybe later.  (Maybe the 20th or 21st, given the change from October 5 to 7.  I wouldn't sweat it.  If you would like, once the baby is born, get the friend to do a DNA test with you (at a certified lab, and go with him).  But if you do that, tell him it's pretty certain that he's not the dad, you just don't want to wonder forever.

[HHOB]

I had an early ultrasound on October 11 saying that I was 9 weeks 2 days along, I have never had a regular period and I can't exactally remember when  my last period was...

[AnnieBrooke]

Hi, HHOB, do you know when the first day of your last period was?  Because babies grow at different rates, an 18-week ultrasound is not going to be as precise for the purposes of dating as (for example) an ultrasound in your 7th or 8th week, so you really have to read any numbers an 18-week ultrasound gives you (including estimated due date) with a margin of error of a few days either way.  Here is what the calculator says for a due date of May 12:

(Imputed) first day of last menstrual period:  August 5, 2012
Probable date of ovulation:  August 19, 2012
Possible dates of conception:  August 15 to August 23, 2012

If your period was indeed August 5, that would suggest your baby is neither growing a lot faster or slower than average, and you can rely a little more on the averages used by the calculator.  On the other hand, if it doesn't line up, then you have to assume that your baby is growing a little faster or slower than average, and count the projected ovulation date as possibly off by a few days.  It would take a stretch to get you back all the way to the 11th, but not to the 15th or 16th, and sperm can live that long in your system.

[HHOB]

I understand this. I'm just hoping they are valid with my dates.

[Combs7]

It could be either. Just because the friend didn't "finish" doesn't mean it wasn't him. You can get pregnant from preejaculant.