I had my 3rd ultrasound today. 😔 update

Linda • Tubal reversal in April 2015, miscarriage at 8w3d in April 2016, ectopic at 6w3d in October 2016. Still not giving up!!
I'm high risk for an ectopic pregnancy. I had an ultrasound at 4w4d but we didn't see anything. They repeated it at 5w2d and we saw a very small gestational sac in the uterus. We repeated it today at 6w2d and it was still just a sac but it hadn't grown any. My hcg level is over 18,000 but it stopped doubling last week. At that level they should see a heartbeat.  They are certain that I have a tubal pregnancy and the sac we see in the uterus is a psuedosac. I go in the morning for surgery. I'm so devastated. I really hope we can save the tube. We tried for 11 months. I was so certain that this pregnancy was gonna last. 
I went to the hospital today. I was sedated for the procedure but they did one last ultrasound before they began. They saw the gestational sac in my uterus with a yolk sac. They said this guaranteed them that it was not it my tubes and wasn't a psuedosac. I go back next Tuesday to see is there's a heartbeat.