Af came on the 15th..but

Okay so my cycle came on very weird this moth to start off with I had light bleeding on Sept 12th, than it stopped that day so my boyfriend and I had sex on the 13th I said for sure my period is coming but nothing, so waited 2 more days the 15th BAM! It came, I stayed til the 19th which pretty much ended, but the first 2 days were very very light to where I didn't wear a pad,okay so on the 19th my boyfriend and I had sex again, it wasn't nothing there, now today is the 21th and I'm still light spotting but only pink and only when I actually wipe me, does anyone have a answer to what all this is meaning I'm starting to get mad knowing that my cycle if this is still it playing tricks on me...feel free to answer anyone !