Not sure I can get pregnant

I'm 24 and boyfriend and I have been together for 3 years. I stopped taking the pill about years ago. I have irregular periods all the time (I'm sure from stress & not being on the pill). Point being, I've never had any chance of pregnancy when we don't use any birth control options. I'm scared to think there is a chance I can't have children. Can anyone relate to this or have any advise?