So frustrated and heartbroken

So I have been trying for 2 years did my 1st

IUI which was a success however my hcg numbers are very low but steadily increasing. I am currently 6 or 7 weeks. Doctors are unsure of what is happening. From day dot they have day told me this may not be viable due to my low hcg numbers and spotting and that I will most likely have a MC. I went for a transvaginal Ultrasound last week. They found a small sac in my uterus but I am not sure if they located a fetal pole. I am trying to stay positive and hopeful but went in for bloods this morning and the nurse was saying the further we get along the less likely this will be a viable pregnancy even if my numbers increase drastically to a more normal range and was talking about me maybe having to get a d&c. I'm heartbroken I have been so positive and hopeful this entire time thinking that some way some how I will receive all that I've prayed for. I feel so defeated.