Menstrual cycle or implantation bleeding?

A day before I was suppose to start my period I used the restroom and noticed when I wiped there was a light amount of blood on the TP. Put on a pad that night and no blood in the AM. All day at work there was no blood. Got home and had sex that night and I noticed there was a moderate amount of blood. Put a pad back on and still no blood? Never been pregnant so I'm not sure if this is implantation bleeding or just a strange period? Happened to anyone else? Sorry for the paragraph.