Insurance Coding Issue

I was wondering if anyone else has had this issue. My doctor's office was originally coding me as "elderly primagraviva" which to them meant that I was over 35 and pregnant. Because of this, my insurance was charging me quite a bit for regular things such as ultrasounds and other standard pregnancy testing.

   After calling my insurance to check on why I was receiving such large bills for things, I was told that the coding they were using wasn't correct and was told the correct code I needed was the "regular pregnancy" code. 

   I have had to go in multiple times to billing to make sure it all got done but they resubmitted all my paperwork with the correct code (they are number codes just to be clear) and now I do not have to pay the copays. I am still waiting on the final two lab bills to go through insurance but all the rest of it came out with me owing nothing instead of the 100's of dollars they were claiming I owed. I also went to my doctor's head nurse and asked her to put a note in my chart that from now on I should only be coded as regular pregnancy for my insurance and so far so good.

   The only thing that I had to leave as the original code was the NT scan test and the AS. Both of those were done at a specialty office which required that I be of a certain age in order to go and have insurance pay so they were unable to change the code there. 

    Has anyone else over 35 had this issue? I believe the same thing happened to my sister who is 38 but she did not fight her bills and I think it may be too late for her to change anything as she just had her baby a few weeks ago and already started paying the bills. She and I have different insurance and live in different states so who knows.