Put away the evil pee sticks, even though it was fmu is it possible that you had a lot to drink last night or went to the loo more than usual? that might dilute it.

Can you get to your Dr? i think that would be the best thing for you right now. Try not to stress (yeah right) - i hope your bt levels come back super high and in 9 months u can scold your little bubba for giving mummy such a scare.