Low HCG ? Possible ectopic?

I am 5weeks today. My HCG has been rising, but at a very low level — Wednesday, it was 15, today it was 27. I’ve been getting bloodwork due to history of MC.

I had an ultrasound today and they didn’t see anything and the doc is concerned about ectopic... Has anyone either been through this and had a normal pregnancy? What about ectopic? I know so little and am just paralyzed with all the fear and what ifs...

*going back early next week for more blood and ultrasounds