Hcg numbers

Hello, I’m 4 weeks 2 days today. I found out a out 8 dpo that I was pregnant. I had my first beta hcg drawn at 4 weeks and it was 55.2. Today I went back in and it was 99.8. There was about 45 hours between the tests. Everything I have searched said that the rate of increase is normal but my OB said bc my numbers were low we would check them again on Monday. My progesterone has been 19-20.

I did have nausea and mild cramping right around the time I found out I was pregnant. It has since subsided and I only feel a little nauseous if I have an empty stomach. Cramping has stopped. No spotting.

My first hcg with my 18-month-old also started out in the 50’s and I went on to have a normal pregnancy. Anyone else experience a slower increase in your hcg and everything ended up ok?