I’m around 5 1/2 weeks

It’s my first pregnancy , my progesterone went from 12 to 16 and my hcg went from 900 to 2,400 in 3 days. The ultrasound showed the yolk sack. One doctor said I was doing perfect and another said I should maybe be concerned because he wanted my levels to be higher. Have any of you had levels like this?!? I’m so so nervous but I’m trying to listen to the doctor who said things were perfect.