Hcg didn’t double..

Seeing if anyone had this previously with positive results..

My last period was august 22nd, but I ovulated late in my cycle. Based on my LMP my doctor saw me Wednesday assuming I was 7w1day. We went to go the ultrasound and she saw the gestational sac and yolk and fetal pole but no heart beat and it measured everything at 5 weeks 6 days which would match perfectly based on my ovulation that was like 8 days later than usual. She did blood work and my Hcg was 10,000 something. She had me go back today 48 hours later for a redraw and my hcg only went up to 12,000 something. My pregnancy tests are still dye stealers and aren’t fading. Should I be concerned with my hcg not doubling in 48 hours?