Sexxxxx

So my boyfriend & I had sex last Saturday with no comdom. He didn't cum in me & I took a plan B pill because we were both scared of pre cum.. I got my period yesterday but the flow isn't the same as usual it's like flowing but not strong as usual. The whole month of December I didn't get my period either. So idk if that has anything to do with it but Him & I didn't do anything in December.. Someone please help me I really hope I'm not pregnant