30 & no kids

So I'm 30 and I don't have any children of my own. I have 4 god-daughters so I get plenty of practice.  I'm dating a guy with 2 children and when all of my friends are with their children I feel like I'm missing something. I'm currently pursuing my bachelors degree & taking my teaching certifications. I'm just hoping by 32 I'll have my own family. Is it normal to feel this way? I've never ever been pregnant should I take a fertility test? My doctor never said anything was wrong, am I just having a midlife crisis and worrying too much?