Toobee~ WOW girl, I'm in shock!!! What a high beta!!
My positive take on this is that you're carrying triplets! Not at all impossible with the good looking blasts you had transferred.
I know how much we can worry about all the things that can go wrong when one has gone through what you have gone through. I really doubt that it could be a m/c or ectopic as they have very strange slow rising betas, especially at first in the case of an ectopic. Not your case at all.
A molar pregnancy is very rare from what I have read.
So, the logical explanation would be triplets.
Are they doing another beta in a day or so to see your progression?
Stop reading all the possible causes for your high beta, you are only making yourself sick. Think positive thoughts...you are prego!!
I'll be thinking about you and your beanie babies!
Love,
Val