This probably isn't what you want to hear, but i had this in May. I didn't miss a period, but had a weird light one, and then when i started opks at what i thought was cd7 they were really dark. They told me pregnancy was ectopic and gave methotrexate. Then...
Betas went 250, 270, 400, 800, 1200, 2400 at 48hrs each time, but my uterus remained empty. They scanned every week. The whole process took 2 weeks before the beta finally dropped and i bled heavily and the HPTs went negative again.
Its a complete and awful rollercoaster that you want to get off but can't, it just seems to have to play out. I read all sorts of miracle stories about how it does work out for people but sadly it didn't for me.
I really hope your in the miracle group. Wishing you loads of babydust...