How can I convince my boyfriend to wait for sex?

It's a little complicated because we've talked about it several times, each ending with a different outcome. First we agreed to wait until marriage, and somehow I've ended up agreeing to do it soon- which I was fine with until I realized I might get pregnant. He hates contraceptives and instead insists on the pulling out method and since he's had plenty of experience I know he can control himself. But I'm still worried to death. Normally I would have just said no I'm ready to do that but I keep switching back and forth on everything! He hates that I was doing that so I promised him sex and now I don't know what the hell to do. Btw he has been a bit pushy but not to the point of threatening to break up with me or anything.