If there is a way to have sex with my boyfriend , besides condoms and birth controul is there any other way to make shour I won't get prag? I'm only 15

Yep, the only sure fire method, ABSTINENCE, until you are at least LEGAL.

Abstinence is the only 100% way to avoid pregnancy and diseases that come with sex.

To be as safe as possible (speaking about your health both mental and physical) You'll have to decide if its worth the risk to have sex at your age. Depending on where you live, there could be issues with one or both of you being charged with sexual assault, rape, etc.
Physically, condoms & birth control are a good start but neither are 100% reliable even when used together. Spermicide, implants, etc. can all be discussed with a physician. Also due to STDs and other risks, its general practice that once you become sexually active you should start getting yearly PAP smears and see a gynecologist regularly (if you aren't already)

I figered thank for answering me

You're welcome.

It's a very difficult decision to make that will stay with you for the rest of your life (trust me on that one). I hope you make the right decision for you so you have no regrets.

The only regrets is moving with my dad but the good thing that came out of it is my boyfriend.