i am 22 years old. my periods are pretty regular. i have not been on birth control for two years and i am sexually active with my soon to be husband. i had a normal period this month starting on the 12th and ending on the 16th. two days ago(24th) i started having mild dark spotting along with some cramping. yesterday was worse with lots of almost black blood(very unusual) and cramping-like a heavy day of my normal period. i used a tampon last night while sleeping and woke up this morning to see black kind of sticky clumps on it and now the blood is lightening up to more of a normal period. i have never had in between period spotting/bleeding/cramping so i am worried. what could this bleeding be only 8 days after my last period?????