Hcg beta levels

Okay so my LMP was 10/3 and period was due 10/31. I think I may have ovulated later than I thought. I found out 11/3 with a faint line I was pregnant! Lines have been getting darker. I got a beta yesterday and it was 123 I’m sure I’m around 4 weeks and if by my period I’m 4w5d at time of beta! I have to go back next week to make sure they’re rising but this number seems so low and I am so scared! I had a missed miscarriage in July and I’m hoping and praying this is my rainbow baby! Anyone else have rather low levels and all turned out okay???