Low HCG levels

A little back story, I had an ectopic pregnancy in January and had my right tube removed. It’s been 6 months and I just found out I am pregnant again. The very next day I went in for my first beta testing, 3 weeks 6 days. Got the results back and it was low (early) 54.4. I’m so scared about this. They told me come back Friday (4 days from first blood test) to see where I am at. Anyone ever been in a similar position? Can you share your experience with me please? Did it get better from starting so low? I know I caught it early (3 days before my period is due), could that just be it?