Many men that have done chemotherapy cannot conceive a child, though it does not mean all. Usually, when a man still wants to have children before having chemotherapy he is asked if he wants to freeze his sperm because it is not for sure if he will be able to conceive after treatments. He can consult his physicians and they will be able to check him and find out. If he doesn't want to, then the best way is to try to conceive that'll be the sure way of finding out. Good Luck! hope it all works out.