Low hcg levels

Hi Mamas and Moms to be !

I had a spontaneous miscarriage on 7/3/22 with twins and 4 weeks later I had some faint lines and then a few positives. Went to get my hcg checked and first beta was 10ml and 48 hours later they were 9ml. Did anyone else have this problem with pregnancy after miscarriage? Trying not to lose hope at the fact it only went down by 1ml but still didn’t double. I’ve also thrown up and felt nauseated and sleeping all day but could just use some words of encouragement to calm me down