AITH for telling my husband to get a paternity test

I’m 38F, husband is 40M. We have two great kids, and he got a vasectomy a couple of years ago after the second was born. We both agreed we were done and didn’t want to add any more to our family.

I recently found out I’m pregnant. It was a huge surprise. We talked about it and decided to go through with the pregnancy. It’s still early days, so we haven’t shared broadly or told others.

He thought he was firing blanks and has made a couple of joking comments about how this baby could possibly be his. I don’t think he’s actually worried, but I also think if I were in his place that I would have doubts too. I know 110% that I haven’t cheated and this baby is his. He is already following up with his doctor about making sure this doesn’t happen again.

I told him we should get a paternity test to show him without a doubt that he is the dad. I offered to do amniocentesis before the baby is born, or we could do it after the birth.

He says we don’t need to bother and it’s an added expense, but I kind of want to push him to do it. I don’t want him to have any doubts whatsoever and I don’t really want to get any more jokes about it.

So AITA for forcing the issue? Throw away account and I’m on mobile if there are formatting issues.