Am i pregnant or not? Please help!!?

Right over a month ago, me and my bf had sex, i am on Microgynon, and have been for 3 months. When we had sex 2 months. Me being very precocious we also used a condom, but the condom split. I got my period right on time. But ive heard about people still getting there period and being pregnant.Like i said its been over a month and i have tender breasts, a little bit of nausea and constipation. I know the are early pregnancy signs, but could it be me just stressing my body out over this. Or could i be pregnant. Im 16 and very paranoid please help :)