HCG BLOOD LEVELS ? HELP!!

Carissa • Trying to convince bby #1 ❤️ mommy to an angel 216👼🏽
Does it count if I went in for blood work on the 2nd day and didn't wait a full 2 days. Can that be the reason my numbers didn't exactly double !? I'm still very early my levels went from the 18th came back as16 19th came back as 30 and the 21st came back as 52.. Should I be worried.?