Implantation or period?

Hi ladies! So i am not on birth control and yes unprotected sex. I was three days late for my period...the first day i was late I took a test and It was negative. I finally get It, but my period was weird! I never filled a pad and It lasted for only two days. The pad was brown discharge, never passed clots, and only would see a pinkish red when i wipe but not bad at all super light and I’m known for heavy periods and bad cramps! I only get slight cramping but It was nothing compared to the usual. What could this be??