QuestionQUESTION: my last period started july 28-30th and it was about 5 days. on the 4th i had sex with an ex but he didn't ejaculate inside me. On the 7 and 8th i had sex with my current boyfriend and he didn't ejaculate inside me. On the 12-13 i also had sex with my current boyfriend and he did ejaculate inside me. I know you'll probably tell me to get a paternity test but i'm just wondering...who is most likely the father here. im so scared..it didn't bother me before because i just knew but now i have two weeks left and this could ruin a lot of people's lives
ANSWER: If you were not fertile on the 4th when you were with your ex, it is not likely that he is the father. If you were fertile on the 4th with your ex, then you would not have been fertile on the 7th or later with your current boyfriend. So it may be possible to rule one or the other out as the father. However, I can't tell you which is the case without knowing things like the length of your cycles and your due date, and how your due date was determined (due dates calculated based on last menstrual period are not accurate).
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QUESTION: Okay...my periods are about 28-30 days long. According to my LMP i am due on May 6th and according to my ultrasound (around 20 weeks) I am due on May 13th. Thanks for your help!
AnswerUsing a 28-day cycle and an LMP of July 28th, and assuming you ovulate 14 days prior to your next period (this is only an average, so it is still not 100% accurate), you would have ovulated/conceived on August 11th, which would rule out your ex. In fact, unless you have very long luteal phases (time between ovulation and your next period), I'd say it is very unlikely that your ex is the father.
You cannot rely on the due date provided by the 20-week ultrasound, especially if you try to use it to determine a date of conception. Ultrasounds use a size measurement to determine gestational age. Human beings come in all shapes and sizes, though, and after 13 weeks gestation, so do fetuses. This is why only very early ultrasounds, prior to 13 weeks (preferably prior to 10) can be reliably used to date a pregnancy.
