Well at this rate, it all depends on you.

You two are having a baby at that time so go marry them if you want to. You don't need to marry them just because they're carrying your child but it is your responsibility to be one of those who'll take care of your child. So what about it if your partner is having a sex-linked chromosome? if you love and value them no matter what they're having in their bodies, just go for it!

Explanation:

It's all up to you buddy, I honestly don't know what I just said, but if I were you. I'd still marry th if it means I get to be with someone I truly love