Though there is some connection between long-term use of steroids and reduced sperm count, I have not heard that taking steroids will cause sterility. The Mayo Clinic site says "Long-term anabolic steroid use can impair sperm production and decrease male fertility." Unfortunately for your situation, "decrease" doesn't mean "erase," and I'd wonder if the guy's steroid use would count as what they mean by "long term" anyway.
You ask "How will I know if I get DNA for baby?" I'll answer the question I think you're asking, and you tell me if I got right. After the baby is born, you and the baby and the supposed father all take a test, involving (I think) swabbing the inside of your cheek with a big, fat swab and sending it off to the lab. With the DNA of both parents (from the swabs), and of the baby, the lab can say "Yes, this is the baby of the two of you," or "No, this is not the baby of this father." If they say that, dig up Mister Steroids and do the test again. We're talking about moral rights here. The baby deserves to know who its father is, and the men deserve to know if the child they are being asked to support and care for is indeed their child.
how will i know if i get DNA for baby? i was confused cuz there was a rumor that when a guy taking steroid it cant make u pregnant cuz the hormone is dead. But im still thinking cuz other say its not true.. :( i was so depressed..
When there are only three days between the sexual encounters, there is no way to know in advance of a DNA test, which person is the father. You do owe it to the baby to get one (not to mention to the prospective dads). I'm sorry you're in this predicament.