Bill question and Mod/high risk

So I received my bill from my first OB appt and it has the charge for the ultrasound and then a separate line for the appointment and under that it says "moderate/high"! My doctor never mentioned anything about him considering me moderate or high risk. The only thing I can think is my weight, but his exact words were "eat whatever you want in the first trimester". I already know that I am low risk for the chromosome items, based on my NT. So now I'm feeaking out and am confused as to why he didn't say anything. Also, he did run an extra blood test but the person that drew my blood wouldn't tell me what it was for. I have an appointment on Tuesday, so I will be asking but I'm also wondering why it showed up on my bill. Do moderate/high risk pregnancy appointments cost more? This was my first 8w appointment and all we did was the ultrasound, the blood test and talk to the doctor for like 15min about morning sickness and the due date. Anyone have a doctor not tell them they were mod/high risk? Can they charge me more for being mod/high risk?