TMI: period is 18 days late. yesterday i thought af was coming. starting having the light pink stuff (ya know the right before period pink) so i put a tampon in because my first couple days are REALLY heavy. well went to change it and there was nothin on it. So i didnt put one back in. went to the bathroom a little while later. and light pink again. so put another tampon in. this sequence happened like 3 or 4 times.... any idea what could be going on?