Doctor is confusing me. UPDATE.

Today I had my prenatal appointment and I am 36+3. Last time I had an appointment, I was 34+3 & I was measuring 34+ some days. So today, the doctor measured my stomach and I'm guessing my baby didn't grow much, because he's still measuring 34+ weeks. So the doctor decided to say "you're 34 weeks." I'm like "no I was 34 weeks 2 weeks ago, remember?" She tells me I'm measuring 34 weeks+, so that must be what I am. Is it possible for me to have been 34 weeks pregnant for TWO WHOLE WEEKS? My due date is sept. 26th (which was October 6th until I had my ultrasound. LMP was 12/31/15.) I know its just an estimate but I am completely confused at this point.

UPDATE: the doctor I go to does NOT do ultrasound measurements. I was told I would only get ONE ultrasound & that was to find out the gender of my child. But anyways, I talked to her, & she tells me almost 5 months later that my due date never changed and it was a mistake. She doesn't remember telling me my due date changed (she told me this in May.) She looked it up and everything and said I'm still due in October (kinda a let down) & she doesn't know where September came from. Which means TODAY, I am only 35 weeks, no more, no less & I actually have 35 days left instead of 25.