Bleeding after my period ended two weeks ago

I got my period April 7th and it ended on the 12th then on the 22nd of April i started to bleed again. light spotting throughout the day. it's gotten to the point where I'd have to wear liners or toilet paper in an emergency. I'm on Trinessa- generic version of ortho tri cyclen. i took one of my sugar pills earlier and i'm down to my last 4.
I haven't stopped bleeding since the 22nd. recently i've been using tampons and when it comes time to remove there's a substantial amount of blood on it. I can't see my OBGYN untill the 19th, and i'm scared. Can someone explain to me what i'm going through right now?
5/3/11