Hi there
If you are thinking of having a sexual relationship with your boyfriend it's really important that you both talk about it and discuss things like contraception. Having sex with your partner should be enjoyable and fun and something that you do because you really want to and feel ready for. If you feel that you are ready, then it is right that you want to take responsibility.
Using the right contraception for you is important, not just to prevent unplanned pregnancy but to protect you from sexually transmitted diseases. It is difficult for you that your boyfriends mum has a different view on contraception, but I think you are being very sensible and voicing your concerns is the right thing to do.
There is lots of information and advice on the Brook website that will be useful in terms of selecting the right form of contraception for you. Your local GP can also provide advice for both you and your boyfriend. I think it might reassure you that you are making good decisions. You might also want to look at the sex and relationships page within the Explore section.
You could also you use the ChildLine message boards and ask some other young people what they would do in your situation.
Hope this helps
Sam