Help please!

Kinda freaking out. Could I be pregnant? I let my BF cum inside me last month during my period and other than that we have pulled out or used a condom. But we have been having a lot of sex especially during my "supposedly ovulation time" (not sure if you ovulate during bc).  Just peed and when I wiped there was a little red discharge. Also my boobs are so tender. Supposed to get my period next Thursday. I've been on birth control for 7 years and never have missed a pill and always take it on time (+/- 30 min). Could I be pregnant?