do I need to worry?

I have been on birth control for two months now and taken the pill at the exact same time everyday, I just had my period last week and I still had a light flow this weekend but I was supposed to start taking the pill again Sunday. I was out camping and forgot to bring them with me so I took it Monday morning at the regular time. My period is still going a little bit (very light) but my boyfriend and I had sex tonight (with no other form of birth control) and I'm worried he may have came in me a little. Should I be worried and is there any chance me starting a day late should mess anything up?