Help! I think. I don't know.

I've never, ever had regular periods. 
Infact, I've only had one 4 weeks ago and hadn't had any for a year before that. 
I keep reading that doctors won't test for fertility until you've spent a decent amount of time trying- but my partner is also a woman, so it isn't as easy as just casually trying. 
It costs money (to pay for the donors travel and expenses) as well as needing to pin point exactly when I'm ovulating, which I can't do, and don't even know if I am ovulating- if I wanted to start trying, I really need to know if I'm fertile first but don't really have the money for specialists. 
How can I do this? 
What needs to be done to test for fertility?