Condom Breaking

Last night, my boyfriend and I had sex and the condom snapped. I mean, he pulled out but I am still freaking out. I've only been on birth control for a week so I know it wouldn't work if he came inside of me. But there's always the chance of pre cum.. should I get the Plan B Morming After Pill just to be 100% sure? I'm only 16 and want to have a successful life. :/