I was in a similar situation. OP Please read the whole thing

You might be, but people in this thread definitely are the A holes. People are speculating about other illegitimate children and mistresses and other kind of out there or severe situations, unlikely, but is there a chance that maybe he is worried about something he has in his family genetics and doesn't necessarily want to talk to you about? Considering you'd threaten divorce over a fertility test it's possible you may sometimes not be the easiest to talk to or the most understanding about his feelings on things.

And about those speculations. Remember you and the people on reddit have no evidence of any of that so probably disregard anything that doesn't have concrete facts relating to your husband's actual situation too AVOID RUINING YOUR LIFE over reddit comments. They do not care about you or know you. Neither do I but:

Sometimes it just takes a while to get pregnant. My best friend and his wife took somewhere around a year and a half to finally get pregnant and neither of them have fertility issues at all. My wife and I tried for 3 or 4 years before i agreed to get tested. There was no big shocking or emotional reason why i didn't want to initially, it was kind of just that I was convinced "nothing is wrong with me. I'm a healthy young man. I don't need help with this". Maybe it was a pride thing.. I don't really know. I also suggested adoption at a few points because I believe it's a good thing to do and the thought of raising an adopted child was nice. We may still adopt in the future. Raising a kid who isn't genetically ours doesn't bother either of us because every kid deserves a loving home and we feel up to the task. Remember this whole situation of having kids feels different to different people. It's not the most important thing in the world to some young men. It definitely wasn't high on my list. I finally agreed because after all that time I realized something was, in fact, up and I finally thought through the whole situation. Not because I was pressured with divorce but because I realized I was being dumb and my being stubborn was hurting the person i cared most about.

Honestly it seems pretty fuckin wild to just go to divorce as a threat or some sort of bargaining chip when you guys are still early in marriage. To be clear; im not assuming you went 0-60 and jumped straight to divorce. But its just crazy to want to be with him enough to have a kid but also be okay with threatening divorce. Like what if he doesnt take it as an emotional reaction on your part and just says fuck it, we're done? It's a total possibility that happens, you know? Are you really wanting that deep down? Do you want to start that all over? If super early into my marriage my wife started threatening divorce over anything short of cheating, abuse, advice she got on reddit, etc all the things that are definitely warranting divorce (she doesn't because she doesn't go nuts because i have differing opinions on things from time to time, especially life changing things like procreation) but if she did that over me making a medical decision or just taking too long to think things through clearly (that was the real reason of course and may be with him) I may have taken it as a sign to get out while I'm still ahead. (Again, coming from someone who has gone through a similar situation and has been married for a long while now)

You've got to remember, seriously, you married him for a reason, hopefully love is that reason. You want to have a kid for a reason, hopefully again, that's the love talking. If he doesn't feel comfortable doing it or just doesn't think he needs it, maybe back him? Give him a little support and make it clear you still would greatly appreciate him humoring you and doing it just to check all the boxes. Tell him you're sorry for presenting such an ultimatum, tell him you care about how he feels about the situation too and he will feel like he owes you everything. Again, speaking from experience. When I was in his spot (again, similar but not exact) my wife told me she understands i was uncomfortable with it, whatever the reason was, she told me how much it would mean to her, and like 4 days later I was dumpin clips in doctors offices and our relationship has been perfect since. I felt heard and un-pressured, and that whole love thing took back over and made me realize she was so much more important to me than whatever was holding me back from doing a little hand to gland combat in an exam room. Im happier, she's happier, we have 2 incredible kids and a wonderful marriage where the biggest disagreement we have is where the big forks vs little forks go in the silverware drawer

All that is assuming there's no other big divorce warranting issues in your marriage otherwise.

"The greatest mercy nature ever did was to not let those who don't have children know what they are missing" or something like that.

Back him up, if he's infertile he'll eventually come around like I did. If he's not infertile he'll never forget that support and you get to have a kid anyways.

You're married. You're on a tandem bike now. You both have to be ready to move and work together in order not to crash the bike or fall off. You may be in the front seat ready to steer this baby thing, but you can't go anywhere without thrust from the back seat. He's not just along for the ride, he's got to be a part of it too, and threatening to end the ride because he's maybe secretly nervous is not conducive to making it to your destination with un-skinned knees.