Anyone have this happen???

My last menstrual period was on May 30th 2019. By today, I should be 7w5d. My cycle is normally 44 days though so I think I ovulate late. On the 10th of july I have a vvvvvfl on a blue dye test and on the 16th I had a DARK positive of FRER. On the 19th (yesterday) I had my HCG beta blood test and this morning I found out my HCG is only 148... my breasts have been sore and very swollen for two weeks, and about 5 days ago i was very nauseated. In having sporadic cramps (if 1 was no pain and 10 was a period cramp, it would be a 6), and two days ago I had super bad lower back pain. When I had my blood work done, I also had a transvaginal ultrasound. They could not detect any sac. They extensively searched my uterus and tubes, and noted that I have a partial septate uterus.... what are the odds that this pregnancy is viable? I go back monday and Wednesday for blood work..