HcG didnt quite double ? 😕

So I went for my second beta HCG blood test today. I got the results, but the numbers didnt double? they almost did, but not quite. I did go a little earlier that 48 hours though.

My doctor doesnt seem concerned. she says the numbers look great for being 5 weeks 1 day. She put me on 200mg of progesterone once a day [only because I've had 3 miscarriages already where hcg levels went up, but never doubled, then dropped down]

I saw a gestational sac through a transvaginal US wednesday 7/17 and it measured 4 weeks 6 days.

Do my numbers seem alright? I'm just so worried about miscarrying again that I'm worry myself to death 😩😖