hcg level was 71?! I'm scared

Hi so I found out I was pregnant on march 24th and then on the 26 I went to the hospital had a little cramping no bleeding they check my hcg and it was 71 I was 3 weeks and 5 days?! Is that low ?! My ob said it was great and that he wasn't even going to do a follow up blood test which make it even harder on me because I want to know if my numbers are going up I don't want to miscarry again😔 plz comment what was your hcg?! I am 4 weeks and 1 day today And my due date is dec 5th!:)