QUESTIONS! Don’t bash

So like, I’ve been sexually active since my period ended as it shows but since the 18th I started spotting. I know it isn’t my period because I’m a heavy bleeder and this this like PINK / it doesn’t even fill a liner , the thing is, it’s been going on and off you could say? And it’s been 4 days . I have no idea what it could be so my question to you girls is , could this be ovulation bleeding or implantation bleeding ?