pregnancy

[lostandconfused33]

my last menstrual period was November 3 I have a 21 day cycle I had sex with my boyfriend November 2 and 9th. I had sex with someone new the condom broke on November 14. December 12 I am 5 weeks 6 days according to a vaginal ultrasound. When did I conceive and who is the father?

[lostandconfused33]

Thank you so much. I had the ultrasound done at Northland family planning they had me write down my first day of last period

[AnnieBrooke]

It is worth discussing the issue of one boyfriend followed by another with the person who is doing the dating of the pregnancy.  It wouldn't be the first time they have had this question.  I have been told that women ovulate 14 days before their next period, no matter how long or short their prior cycle is.  But if that is true of you, it does not to match up with the "5 weeks 6 days" count you are getting.  

You haven't said where you got the ultrasound or who read it.  Sometimes women go to the ER for this kind of thing, not a very useful place to go.  Sometimes they go to the Birthright type of centers.  If you went to your own trusted ob-gyn who has an ultrasound tech that works there in the ob-gyn clinic, and you got a vaginal ultrasound, and it was read by a doctor, then you will have gotten the best quality of ultrasound you can.  But again, if they didn't tell you that this was based on the measurements of the embryo and not on your report of when your last period was, you would need to find that out before you trust the numbers.  The dates of having sex are so close together that if the first guy ejaculated in your body on the 9th his sperm could have still been alive in your body on the 14th.

I don't know if a doctor will go off what a woman reports to be the first day of her last period if he or she sees that the ultrasound says something else.  It is possible he wouldn't see that the ultrasound said something else than the files say.  Usually the first day of your last period is asked of you by a bored nurse who writes it down way before you ever get to an ultrasound.  You are within your rights, if you did all of this at a good ob-gyn's, to ask whether the 5 weeks 6 days count you were given was just based on your self-reported first day of your last period.  And yes, if a woman is not sure about which guy is dad, she really needs to say that she is not sure of the first day of her last period, or at least to ask that the estimates of her pregnancy be based on the ultrasound measurements only.  Women with irregular cycles do this.

If you ultimately get a date that suggests ovulation on the 14th or so, you are in kind of a fix, since both guys could certainly have had sperm in your system at the same time.  In that case, if you can afford it, do the prenatal DNA test from the DDC or Ravgen.  It is really the only way you would know.

[lostandconfused33]

so should I not tell them when my last period was? that way they can only go off the embryo because it seems like if I tell them they will go off of what I say

[lostandconfused33]

I was going to have a non invasive paternity test done at 9 weeks which would cost me $1700 but was trying to get a little more clarification on my conception date. thanks for your help and advice

[lostandconfused33]

so in your opinion do you think if conceived on the 15th it would be the other guy and not my boyfriend

[lostandconfused33]

ok thanks I will have another ultrasound done and maybe call the place back to ask them how they caculated their theory

[AnnieBrooke]

And if you do get another ultrasound, please tell them you want to know an estimated due date and number of weeks along that is based ONLY on the embryo's size and developmental markers, not on the first day of your last period.

[AnnieBrooke]

If your periods are always 21 days long, you would have theoretically ovulated on about the 10th of November.  But if you were 5 weeks 6 days on December 12, that suggests you conceived around the 15th.  How good was the ultrasound?  If you went to a private ob-gyn who you think is good, I would tend to put the most store on the ultrasound reading.  But that would depend on whether he used the actual measurements of the embryo to compute how many weeks along you are.  If he just told you how far along you were based on when you told him your last period was, the ultrasound is not useful for dating the pregnancy.

Can you get another ultrasound?

[lostandconfused33]

I'm sorry just looked in calandar it is every 21 days on the clock. I write everything down

[lostandconfused33]

august it was 21 day cycle september it was 24 day cycle then october it was 21 day cycle

[lostandconfused33]

typically my period lasts 4-5 days in November it only last 3 days.

[AnnieBrooke]

Is your cycle always 21 days, like clockwork?

[lostandconfused33]

I'm not sure if it was based on last period or embryo. sorry. Yes the ultrasound was done on Dec 12th. what is the intervening days? not sure what that is

[AnnieBrooke]

Also, you said, "December 12 I am 5 weeks 6 days according to a vaginal ultrasound."  What day was the vaginal ultrasound?  Was it  December 12, or was it earlier and you have added the intervening days?

[AnnieBrooke]

Your 21-day cycle is the wild card here, but having had an ultrasound that told you 5 weeks 6 days is helpful.  Was that count of your weeks pregnant based on your report of when your last period was, or was it based on the measurements of the embryo?