E.R.
Your uterus wouldn't feel pregnant yet! That is so odd that she would say that. Your baby is just a few cells right now. How could she feel that?
If you are having positive blood and urine tests, the next step would be a trans-vag. ultrasound to see what's going on. You COULD have fibroids, but you could also be pregnant. Your doctor should have answered all these questions for you. Did she do an ultrasound?
I had a couple of trans-vag. ultrasounds with my last pregnancy because I was spotting at around 4-5 weeks. They couldn't even see my baby on the ultrasound at that stage. I had to come back at 6-8 weeks so they could find him and make sure everything was all right.
SO I would wither get another doctor, or wait and get the trans vag ultrasound to see what's actually happening. I'm sorry you have to wait like this, I know it's so hard.
The thing any OB should be doing, especially with your history, is have you come back every couple of days to do a blood test and measure your HcG levels. If they keep going up, you are pregnant and your risk of M/c is very very low.
I hope this helps, and please, find a new OB.