Theoretical Query

So I’m a few days late on my period and not super worried at this second but I realized if I happened to have gotten pregnant it would be the child of one of 2 men I have been with recently. The guy I’ve been with the most, and most recently, we are about 99% sure can’t father a child without hormone therapy due to a medication he was on while he was growing up. My theoretical thought is; would it be unreasonable to want to stay with the guy I’m currently with? Or should I feel obligated to go back to the baby’s father? I know my answer I just want to see what you ladies think!