When did your ultrasound find the sac?

TRIGGER WARNING ⚠️

I went to the er around 2 am this morning due to cramps, and my BFP were getting lighter every time I tested. I have terrible anxiety so I felt I needed to be seen at that very moment. They confirmed my pregnancy with a test . And They couldn't find the sac in the ultrasound. So they did blood work and my hcg levels are at 116. So this means I'm either too early for the ultrasound to pick anything up (if my hcg levels double in 48 hours than that is most likely the case) if the levels get lower it means I'm going to miscarry soon. They are saying im 6 weeks. But I believe I’m only 3/4 weeks. I’m only 14-15 DPO so I’m praying very hard that I’m still early and that my hcg levels are normal and they will find the sac the further along I get. I’m not longer cramping and the cramping I was having was not too bad or painful. I just went to get checked out because I got worried. Any advice? What were y’alls original hcg levels when you first found out? Did anyone else have trouble finding the sac?!