Question about HCG levels

Sara • MC 10/2015 at 4 wks & MMC 10/2016 at 8 wks + 2 days. Currently pregnant with my rainbow, due 11/2. 🌈
Went in to test HCG after my BFP and it was 318. 2 days later, went again and it only rose to 518. I'm on progesterone. Not sure how far along I am, as I never got a positive OPK last month (Was surprised when I got my BFP!) I feel like my levels are low/ not rising as quickly as they should be. I've had 2 miscarriages and am sooo anxious about everything 😣 Any positive stories to share?