Pregnancy

So I posted a picture last week of my pregnancy tests... so update my blood work came back positive and my levels hcg was 55 and got blood work done again on Saturday and got the results today my hcg level is a 72 and progesterone is 30 so that good but my levels aren’t exactly doubling so I have another blood draw tomorrow at 11:10 and I’m nervous I’m afraid it’s not a viable pregnancy... I keep asking questions but they don’t have enough to answer I’m assuming... am I freaking out for no reason? I’m worried I’m gonna lose my baby has this happened to anyone else?