nervous,what do i do?

Me and my boyfriend had sex 2nights ago and yesterday i noticed a little bleeding so i figured it was my period so i used a tampon and then when i went to go change it there was nothing but discharge.So i figured it was nothing then today the same thing happened and i have had a little cramp here and there.I am on birth control and we didn’t use a condom but he didn’t bust on me.So what should i do??