Pre cum?

So yesterday I was giving my bf a blow job, he cummed and he didn't clean off his penis or anything and he put it in, he thrusted inside of me 3 times so he was in me probably about 15 seconds before I told him to get out lol he didn't cum and I don't know if he pre cummed? I'm on birth control and I take it everyday and 5 days out of the 7 day week I take it the same exact time, should I be worried?