Anyone else not seen a doctor yet?

I have had 5 appointments at my gyn/OB office but every time I only see a physician assistant or ultrasound technician. ( I am 18weeks 1day)They said the doctor will see me at my 20 week appointment and that its common to not be seen by a doctor yet till then aka later in pregnancy and that a PA is fine. Anyone else get this response or should I say screw this place and find somewhere where I can actually speak with a doctor? The only reason why I have stuck it out this long is because the doctor is highly recommended by many hospitals and patients but he is always booked up and I am a high risk pregnancy with identical twins. Also how many times am I supposed to be making an appointment in a month in the second trimester?