When and how did I get pregnant?!

[mdans89]

My periods are usually 30 or 31 days apart, but in December I had a period on the 4th and again on the 31st. On the 13th I had intercourse and took the plan b pill the next day. I got back together with my ex and we had intercourse almost everyday since the 15th of January. On Jan 27th I had a negative pregnancy test and two positive hpt on the 29th. Now that my bf and I got back together, we tried for 2 years for another baby and I'm not sure if it was all the making up we did but I'm not proud of the fact I had intercourse with him and the guy I broke up with on the 13th. So I took plan b hoping to prevent a pregnancy from occurring. The boyfriend is thrilled I finally am pregnant again, but conception dates say anywhere from Jan 11-20.. most saying Jan 15th. I have my first doctor appointment on Feb 15th and I'm hoping the conception date is a little later and that the first response pregnancy test was just able to pick up slight hormones? Is that possible? Did plan b protect me from the 13th and my actual ovulation day should've been around the 17th.. did I get pregnant from having sex far too much after taking plan b?

[AnnieBrooke]

Here is what the conception calculator gives for a due date of October 8:

Probable date of ovulation:  January 15, 2013
Possible dates of conception:  January 11 to January 19, 2013

Nothing seems to suggest that it would have been before the 13th, which is too bad because if so, it could have ruled out the second guy.  So though it seems somewhat likely that it is your boyfriend's baby, because his sperm had the most opportunities, if you ovulated right about the very moment you took the Plan B, both guy's sperm would have been present in your reproductive tract then.  Given that the Plan B obviously didn't work, you really are in the position where you won't be able to know until a DNA test is done.

[mdans89]

The doctor based the date of conception off the ultrasound because my periods are too irregular to figure out my ovulation days and what not. I had a period October 4th, November 6th, (before october I didn't have a period for 3 months), December 4th and December 31st... I've been all over the place anywhere from like 21-35 days with periods.

[mdans89]

The doctor said oct 7th bc of my last period and the ultrasound said oct 8th.

[AnnieBrooke]

What due date did the doctor give you?

[mdans89]

My u/s was on 2/15, and the doctor said the conception date was 1/15 give or take a day... My boyfriend and I did have intercourse that day, and that's also the day after I took plan b though...

[mdans89]

Thanks so much for your help! I will keep you posted!

[AnnieBrooke]

Hate to say it, but Plan B only claims to be effective in 7 cases out of 8.  

It seems likely that it is your boyfriend's baby, because his sperm had the most opportunities, and given that ovulation obviously occurred, it will most likely have done so before and not after Plan B.  (Because Plan B is designed to keep you from ovulating.)  But if you ovulated right about the very moment you took the Plan B, it would not work that fast.  (That's probably where the 7 out of 8 comes from.)  If that is when you did ovulate, since both guy's sperm would have been present in your reproductive tract then, you really are in the position where you won't be able to know until a DNA test is done.

When you get a 7-week or 8-week ultrasound, they will give you a due date and a gestational age that is presumed to relate to the first day of your last period.  If you ask them at that time (using the word "conception") they will also give you a guess as to when conception occurred.  What you'd like to see is a due date that (when plugged into a conception calculator) relegates conception to before the 13th.  Come back onto this forum and add to this thread when you get an ultrasound, and I'll help confirm your counting.

[mdans89]

I had sex with D the whole month but a slip up on the 13th.. we just got back together last week after a couple month split. Plan b is supposed to delay ovulation or help prevent implantation that's why I'm at a loss for words. Unless it did delay ovulation and first response picked up the slightest bit of hormones?

[AnnieBrooke]

If you did have sex on the 11th, that is certainly a possibility.  If your cycles are usually 30 days long, however, there is also the possibility of a later ovulation, like on the 16th or 17th.  The trouble with that idea is that is seems like Plan B would disrupt ovulation.  Thing I'd do in this situation is google the Plan B website and see if there is a FAQ about how soon a woman could get pregnant after taking it.  They might well have an 800 number you could call and ask, as well.  But (and I hate to say it, because if I understand your original post correctly, any sex before the 13th was with the guy who is not presently your boyfriend), it does seem like there is a pretty good chance that you were pregnant before the 13th.

[mdans89]

Yes I had sex on the 13th and took plan b the 14th of January. My cycle has never been less than 30 days so I'm not sure why in December I had a 27 day cycle. I'm wondering if sex with my bf on the 11th is what got me pregnant so plan b didn't work in that case? According to web me ovulation where you enter your last 3 periods, it told me Jan 13-17 ovulation.

[AnnieBrooke]

Here are the dates as I can tell from what you wrote:

       December 4  first day of period

       "On the 13th" sex with two guys and Plan B [13th of December?]

       December 31 another period

       "On the 13th" sex with two guys and Plan B [13th of January?]

       Sex from January 15 on

       Negative pregnancy test January 27

       Positive pregnancy test January 29


OK, let's assume that when you said "on the 13th" you meant in January, or you wouldn't be worried, right?  It sounds like you have about a 27-day cycle, which puts ovulation at about day 13.  Would that be a normal cycle length for you?

The long and short of it is it's hard to tell why you are even pregnant, since just by counting alone the timing refers right back to the 13th, which of course is when you took Plan B.  The only thing I can suggest is that you were already pregnant on the 13th.  How sensitive was the pregnancy test you took on the 27th, and was there any chance your urine was dilute?