How to react?

My husbands cousin just announced her 3rd pregnancy. I can't help but be jealous since we haven't even been able to conceive 1. Everyone keeps asking us when we are going on have a baby? And "come on we need more cousins...." It just hard to know how to answer since we are trying but don't want the pressure of everyone knowing. I just want to go back to being happy for everyone and not jealous it's just hard sometimes. Everyone in my husbands family is having babies including his brother who they weren't even trying, why is it so hard for hose of us who want it with even bone in their body? Sorry just a rough day.