Spotting between periods not normal for me any ideas please? Anyone?

[BabyDoll20]

I had my period on March 5th thru the 10th. On Wednsday March 11th I had sex and yes it was unprotected. On Tuesday March 17th I began having some light bleeding more like spotting. It stopped and then started again around 9 am on Wednsday March 18th and has continued thru today. It has been a light pinkish or brownish color. I have always had a normal period and have never had bleeding or spotting between periods before or after sex. I also noticed some light crampiing last night,no major pain just a very mild cramping feeling is what it felt like I guess. I was planning on calling my OBGYN on Monday. What could be the cause of this

[unknownjourney]

Anything else going on?  tender breasts, more bathroom trips,?  Have you taken a PG Test? Some people have this kind of bleeding when they first get pregnent.