plan B / can it cause a miscarriage

Soooo. I had unprotected sex condoms broke , took plan B. Ended up getting my period and it was soooo heavy I had to be changing every 5 minutes I couldn't even walk and I had painful cramps that I had to miss work.... I always saw some stuff in my pee idk how to explain it and I also had a lot of clots ... please help me out ... I'm really devastated right now.