Hi again, you responded to my post this morn and here you are with your own stuff going on too!
Im sorry to here the pos, then neg's. Its awful. It sounds like a chemical pregnancy to me, They are alot more common than we realize. Mine happened at about 5.5 wks. I first tested 4 days over and had a pos, then 2 days later, pos was there but fainter, then had blood work done which showed hcg declining. Then heavy bleeding started about 4-5 days after seeing doc..awful, clotting, aches etc.

I hope this is not the case for you though, but sounds similar. Pray it was just a dodgy test and your doc can tell you whats going on.
Let us know how you go!