HELP!!!!!! Positive prenatal screenings for downs

I’m very upset with my Dr office may I add. First I get a call that said a concern with your test and we need you to come in but we can’t get you in until January 3 I then ask should I be worried they said No so why give me this call with so many days away to wait?! So I called back to ask for more details and the said that the policy said the couldn’t say over the phone and we are all out of appointments. I was furious because I didn’t understand the reason to call me to add worry or stress for the next 12 days to find out what was going on. So I told them well since you can’t give details I’m on my way so that you can tell me in person. I get there and they some how found an appointment to schedule for me that day. Sooo, I just took my second round of blood tests which was 4 days prior to call. I was about 16 weeks and 4 days but I get my test back and they had logged I was 19 weeks and 4 days for fetal gestational age which is about 3 weeks plus days more advanced than what I really am. So I tested positive for downs with increased risk greater than 1 and 10. I was sooo shocked prior to reading results Because this is indeed something to worry about as the nurse told me there was nothing to worry about over the phone. So my question is Do you believe the over estimation of the gestational age could change the result of the test ? Posting anonymously until I come to a conclusion with this.