Slow rising HCG

I got my first HCG test done at 6 weeks and 2 days and it was 36605 and my second at 6 weeks and 4 days and it was 49621 it clearly did not double but I ready the higher it is the less likely it is to actually double and saw this article saying a rise of 35% is normal with high HCG levels and with how far along I am. I have no bleeding no cramping or anything. I go in for an ultrasound November 9th when I’ll be 8 weeks to check on things. Anyone had similar numbers and had everything turn out okay?