Hcg levels

So I had a miscarriage in December and I just found out I am pregnant again :) my dr had me come in to get bloodwork and make sure my hcg levels are doubling every two days...My first test came back good and I get my test 2nd results back tomorrow but I was wondering if anyone has been through this and got a good outcome with their levels being a little low in te beginning. I just want to be prepared so any info helps !