Just like Amanda said, call your dr and get your beta drawn and a progesterone. I asked for a progesterone due to miscarriages and the Dr completely agreed. Good luck and the sooner you can take it if you need to the better!! Good luck!
With that history, I would try to get your progesterone checked asap to see if that is a problem. Also, I would take it SUPER easy for the next week or two...or longer. Good luck babe!