had period two times and spotting all month long????

i got my period on the 26th of june last month and then again on the 8th of july. between those periods i got spotting that was either dark brown, dark red, or black. then after my period was over on the 12th of july i got spotting that night ans hasnt gone away at all since then and is still either dark brown, red or black. I have been on birth control and still am but dont what it could be. I am on the tri-cyclen any thign would be nice on what it may be.