Hello i wish u can help me about my problem,im sorry my friend dont remember her last period on that month, she having sex with the first man on the 2nd week of december 2nd man is dec.26 and 3rd man is dec.28 .and she gets pregnant ,then she delivered her baby sept.19 , i just want to know if who is possibly the father of the baby? Is it the first .2nd or 3rd man?.
Working backwards from the delivery date her LMP should have started on/about 12/14/2015. In that case, having sex the second week of September, 9/7 to 9/14 it is VERY unlikely that the 1st guy is the father. It is likely that your friend was just about to begin her period and would not be fertile.
December 26 would be day 12 of her cycle. She'd be at/near her peak fertility.
December 28 would be day 14 of her cycle. Again, she'd be at/near her peak fertility.
The dates are just to close together. It is VERY likely that the 2nd or 3rd guy is the father but we can't predict which.
She'll need a DNA test.