I have pcos and i am now pregnant. i had sex protected and unprotected within 7 days how can i determine who the father is prenatal?

With documented PCOS, there are long intervals between menstrual periods, and w/o testing to date ovulation, it is not possible to ascertain dates of fertilization pre-natal. Amniocentesis can isolate fetal cells from which DNA can be compared to male parent, but DNA samples would be required from each male.

If your ovulation day is very predictable and you can determine who was the one who had unprotected sex with you within 5 days before your ovulation date, you may be able to figure it out. I think that would be the only way to determine paternity prenataly but bear in mind that this is only a guideline.