I think it is very unusually for someone to miss to AFs & then have two negative BT but still be pg. That said, I have read elsewhere on the net of a woman doing 4 stick tests and I think 4 blood tests before she showed up as pg at 12 weeks.... so I guess that it is possible.

Go get the ultrasound. I think there may be something else going on there. There are lots of other reasons for AF stopping and for your stomach to bloat like this.

I know fibroids can cause the stomach to look like this and i think they can also interfere with your cycle as well. If it's that it will show in the ultrasound. It could also be a hysterical pregnancy but that's extremely rare, so not likely.