Am I infertile??

It's been a long-time question of mine whether or not am I just infertile.

My periods are irregular, as in it skips months varying from 1-3 months, but when it arrives, it ranges. I've also never been pregnant.

I've been having sex since I was 15 and I've had guys I've dated that we started off using condoms and then stopped using them entirely when we would have sex. Of course there were guys who I just had sex with for fun, but I've always made sure we used condoms. I've taken Plan B on only two separate occasions in my life, but I doubt it's done anything weird.

I'm 23 now and I'm finally in a relationship I can see myself having a future in. Again, we started off using condoms for like, 2 days, and then we stopped. We've been together for a year and we have sex about 1-2 times a week. He, like others, have questioned why haven't I at least ONCE, got pregnant, but it's not like we're really trying yet. I've explained to my partner all of this and he suggested I simply go see a doctor about it. My only response to that was that I would go if it was serious or potentially serious because doctor's visits are expensive. Lol.