I am scared I am pregnant..

Me and my boyfriend had sex (with a condom & I am on birth control) about 2 weeks ago. And I am about a week late for my period (my periods have always been irregular though) and my breasts have been so tender. But I took a pregnancy test about 5 days after sex and it was negative both times. Should I take another test? I am not sure what to do. Should I be worried about the tender breasts? Please comment any thoughts, it would really help!!!