AM I HURT OR PREGNANT OR SOMETHING?!

I'm on birth control, I've had Nexplanon for two months. Since it was put it I had brown discharge constantly but that's normal. I stared being sexually active and in the last two months have had sex four times. After the most recent one on Monday, I started bleeding again. I didn't know if it was my hymen breaking or if he tore something inside or if having sex jumpstarted my period or something, but I'm nervous. I have a few blood clots and the blood flow has been getting lighter but has this happened to anyone else? Is it normal? Am I pregnant?