Is there a way to fix sterility in males?

My fiancee and I are going to go see a doctor soon for this, but I just want to know what to expect if we get the worst answer. We've been trying to have a kid for about 2 years now, and I'm still not pregnant. His *** is always clear, always has been sense we got together, but I think I MIGHT remember a few times when it had spots of white in it, not sure though. I know from being with my ex's that it's normally not clear, but I didn't think much of it until recently. Then I looked it up and many people said he's either producing very few sperm or none at all. I know that we could always adopt (I want to adopt a baby/kid in the future regardless) or use sperm donors or something, but there's just something about having a baby with the man you love. If I can't, then I'll just have to accept that, but if I can I really want to. So I'm not asking what the chances of him being sterile or not are, but if he is sterile, is there a way to get him to produce sperm?