Someone explain please

Okay so I was diagnosed with pcos when I was 15 I’ve never had regular periods I’ve tried about 7 different types of pills and the shot I ended up having a miscarriage in 2017 while on the shot and haven’t been on birth control since. We’ve been trying for about a year and no luck I went to the dr and she said the only way to treat my pcos is birth control to get a regular period but that’s never worked before and she said she cant refer me to a specialist until we’ve tried for 15 months. Once we reach there I will go but I’m just curious and don’t know how fertility treatments work so could

Someone explain how they work and if they would work since I don’t have a period?