Hi,
Welcome to ehealthforum,
If you had a period in between having intercourse with two different people, then the second intercourse (that occurred after periods) would be the one leading to pregnancy. If there was no period in between, then it is difficult to tell who would father the child. If your due date is known (completion of 40 weeks of gestation), then you can count backwards to from there and look for your probable conception dates (probable ovulation time). You can also request your gynecologist/obstetrician to get early âdatingâ scan done for you to confirm the probable date for conception (which will be based on baby/fetus growth and development stage). For accurate results, you will have to get a Paternity test done. All the best.
Take care.