Does anyone else have Circumvallate Placenta?

I was told at 20 weeks that something was wrong with my placenta. I was sent to the high risk doctor where they told me I have circumvallvate placenta. If the baby was measuring good and the blood flow with the placenta and umbilical cord was good then I could go to my normal OB appointments. Everything was good and my OB said to keep check he would do an ultrasound every four weeks. At 26weeks everything was still looking good. I just had my 30 week appointment and the baby is measuring 26 weeks. They will be doing an ultrasound in two weeks to see how things look and could be going back to the high risk doctor. I'm really nervous about the appointment coming up. If anyone has or had this how did the last part of pregnancy go and delivery?