Possible miscarriage

Two days ago I went to the ER due to severe bleeding, cramping, & back pain. My HCG was 5,371 which the ER said is really good for being so early on. My biggest concern is I saw an OB that morning & he saw a gestational sac & baby. Yet the ER transvaginal ultrasound didn’t show anything. I am awaiting my blood work from today from my doctor to come back by Monday to see if my HCG has increased. If not then it will be ruled as a miscarriage. Has anyone else been through this? Did you end up having or miscarriage or was it

considered 1st trimester bleeding? I am dreading the worse. 😓