Being that one friend without kids

Hello. I am 21 years old and I'm married. I don't have any children. My husband and I own a house and are very very happy together. All of my friends have children, and I am having a hard time fitting in. I love my friends but I am feeling left out and none of them understand why I don't have kids yet. My husband goes away lots for work and often without any notice, so we don't feel we are stable enough to have kids yet. I am having a hard time with talking about diapers for two hours straight and feeling like my friends don't care about what's going on in my life because it all seems minor to them. I am feeling like I need to discover some friendships with women who don't have children. Has anyone else gone through this? I also feel like by the time I have a child they're kids will be like 7 or 10 and it will seperate us when tht happens too. Just having a hard time finding where I fit in. Does anyone have any advice? Thanks in advance