Birth Control

Helloooo I've been considering various forms of birth control and I could use some input from unbiased, thoughtful sources.
I'm seriously elated to be dating my boy I've been pining after for around 8 months. I am fully aware of how young we are (15 and 16) and I understand we have a lot to learn, but we're ridiculously happy and pretty damn in love. I don't really plan on having sex immediately but things have been going really fast and I'm surprised at how much I've changed over such a short period of time. Of course I would give the idea plenty of time to ruminate and it's a discussion I've had with my mom and my boyfriend. I've been honestly considering sex for a while. What forms of birth control should I look at? Any additional wisdom is sincerely appreciated. 
Here are some facts to consider:
- I know he's had sex with one other person when he was younger. I have not. 
- I really don't want to deal with the pain of IUD insertion and the irritation that comes with one.
- I have a history of breast cancer in both sides of the women in my family and they believe the pill had something to do with it.
-I'm told the pill has had negative side effects like unwanted weight gain but my mom claims it helped her lose weight and clear acne. I'm down for that. 
- any birth control would be coupled with condom usage 
Thank you!