Hi Kayla,
I hear your dilemma, yes it is possible to be pregnant and for whatever reason it not show on the HPT (there are a couple of ladies on the threads who didn't get positive HPTs for months). The best thing you can do is get yourself to a DR quick smart for HcG tests - make sure you tell them why it's urgent - they might be able the get the results thru for you today.

Alternatively, when you go to the Dentist, just them you suspect you might be PG. They won't use any drugs etc then that they shouldn't use or they might talk about postponing the work for a bit (middle trimester is the best time to get stuff done).

((hugs)) Try not to stress, arm yourself with some real info from the specialists and then you'll be ok. I hope you get the news you are hoping for!