Got my period 16 days early & this is the 12th day ive been bleeding, its dark brown & usually light, no cramps or breast tenderness, what is this?

Pregnancy?: Check a pregnancy test first. If not pregnant then this could be due to a fibroid, polyp, stress/ anxiety and if you are bleeding heavily - then get this checked immediately

Pregnant?: This kind of abnormal bleeding could be caused by a number of problems including pregnancy, an STD such as gonorrhea or Chlamydia, failure to take birth control pills on a regular schedule. I would suggest you see you Gyn about this