Who is the father of my child

So im stuck in bit of a sticky situation im in my 6 month of pregnancy and ever since ive been 9 wks ive been trying to figure out who the father of my child is.A little background i had my LMP Feb 3, 2016 that lasted about 7 days. I was with Father A from Feb 10, 2016-Feb 21,2016 without protection and he ejaculated all in me. The only reason i question him is because ive been with him for a year without using protection and he never got me pregnant i thought i was infertile. Now Father B i was with on Feb 22 ,2016 my ex until March 13 , 2016 we didnt use a condombut he never came in me .Please help!!!