Do these "fathers" do sperm count tests after their S.O. conceives.
There was a hilarious case around my area last year where the guy ended up with a half asian baby after swearing up and down it was a miracle and gods work that they were able to conceive when his sperm count was technically zero.
I keep hearing guys saying its possible. Yes, if you are on HCG and your leydig cells aren't inert. We know steroids shut down your sperm production thats why it has been explored for use as male birth control.
Just something to think about. Women are devious devious creatures. If you are on steroids and get a girl pregnant get your sperm count tested and do that DNA test when the kid comes around.