Tic. Emotional.

Okay so I'm so sad. My So has wanted a baby ever sense we were in high school (17) and I wasn't ready then. But now we're engaged (21) and I'm totally ready. I have like baby fever I see a baby and I want one so bad. Like I'm ready now I'm about to be done with school he has a great job and we have our own place. But it just sucks that I've been trying for 2 months(he works far away I only see him every two weeks) and I'm still not prego...and I've noticed that my fiancé is kind of kind of sad about it to he hasn't mentioned it to me or gotten upset. But he's always telling me like  let's have a baby and I can't wait till we have our own child. He knows that we'd be great parents. So every time he mentions that he wants a child I get so sad. Or like if we're around friends that have a child already they'll be like so when are you all having a baby and it makes me so sad. I really do want one. I love kids so does my fiancé but these past two months have been very emotional for me because I feel like I'm letting him down because I haven't gotten prego. And he doesn't tell me anything mean. But that's just how I feel.