Since no one form of birth control is 100% and men can have STDs without symptoms- I suggest finding a form of birth control -such as lucknlove mentions AND using condoms on top of it. This will help protect you just in case the condom breaks, or just in case the pill fails.
Make sure to ALWAYS have the guy wear a condom and any method of birth control that would suit you best. There is the birth control pill, nuva ring, depo shot, implanon, etc. In my opinion with personal experience the nuva ring was the best. The shot made me gain a lot of weight as well as implanon, the pill i was way to forgetful for. And nuva ring i put in for 3 weeks and took out for 1 week.
Best wishes!
Condoms ,birth control , abstinence any would work condoms is easiest