Relatively new here. 

Can someone help me before I make a doctors app tomorrow morning.. 

I'm due my period on the 13th, it's usually on time or lateish.. but yesterday the 5th of July, I woke up with severe cramping, period like cramping, I put on a towel, and within minutes I was bleeding, but the blood is brown, and occasionally kind of pink in colour.. is this abnormal bleeding, or implantation bleeding? I had sec everyday with my partner multiple times during ovulation especially on my peak day, and yes we are trying.. any suggestion will be appreciated. Thank you.