so i finished my period last wednesday, it came at my usual time in cycle, i have a regular cycle. But yesterday i started bleeding again, and its not a normal period, its very light and brown. Ive had unprotected sex numerous times during the past week and was wondering if this could be implantation bleeding? Its been going on for a day and a half now and is much the same. I took a pregnancy test the day i started bleeding but im pretty sure it would be too early to tell. Has anyone had this before a pregnancy? Or does anyone have any other opinions on why its happeneing? Any advice will be greatly appreciated.

Also, should i see a doctor?

Thanks.