12dpo spotting? Period? Who knows

So on Oct 30 I got a positive opk. We did the deed the following 4 nights. I began having sore nipples/headaches about 4 days ago. Today I’m 12dpo and started cramping then discovered bright red blood when I wiped. I put on a pad and there was some but not much the rest of the day. About 4pm it completely stopped and hasn’t been back. Thoughts? I’m beyond exhausted from trying to figure this out.

PS. I also experienced dark brown spotting from October 5-7 then nothing until the positive opk on October 30.