Cramping and bleeding after sex

This is my first pregnancy and i'm just at 5 weeks. My SO and i just found out a few days ago so we haven't scheduled a doctors visit yet. This morning we had sex and i've been bleeding and crampy ever since. Its not heavy but its also not light. I've had some breast soreness and nausea up until this point but this is the first time this has happend. Should I be worried??