Irregular Periods and Birth Control

Hey y’all, so I have a question concerning irregularities and birth control. I have an irregular period and was in the pill for a long time but because my doctor and I never figured out the right dosage and I was still irregular I got off of it. It was also causing me to gain a LOT of weight. Now I think I’m ready to have sex with my current partner and I’m wondering if I should get back on the pill or try something else? He’s definitely going to be using condoms but I just don’t believe it’s enough. I’ve also been told that a lot of people who are irregular take the pill so they can get pregnant?! I just don’t know what to do! I’m definitely going to talk to my doctor about this but I wanted to get some other opinions. Thanks for y’all help