Hcg level 70

Dani

My last period was June 24 th found out I’m pregnant July 28th and my hcg is only 70 is that okay my app says I’m 5 weeks and 2 days but my numbers should be way higher then that if I’m 5w 2d 70 I would only be like 3 weeks should I go off when my last period or when I ovulated well I can’t go off of ovulation because I don’t know when I was ovulating I had a miscarriage back in February and I’m worried my levels are were they are supposed to be