Help!!

Abbie
Last month I only had a 3 day period and I normally always get them at the end of the month around the 21st but it came a little early around the 18th then last Saturday I stated spotting and I still am today but it's not real a lot of blood it's really just noticeable when I wipe bout and it kinda looks like there are little bitty pieces in it but I can't really tell now it's turned into like a brownish colored discharge... I'm not cramping and and I didn't last month either and im not on any birthcontrol and I have unprotected sex