Implantation bleeding????

Sooo, my bf and I had sex and then about a week and a half later I had brownish discharge. then later that day it was pink AND then even later that day it was completely red. except it wasn't like a period, it was thin and stringy looking. I've been having mild cramps, diarrhea, and I've been having a lot more pimples than usual on my cheeks. If you've had or know somebody whose had implantation bleeding please let me know if that's what is happened. My period is about 3 days late.