How far gone was I?

Hi, I miscarried a few months ago. I thought I was supposed to be 15 weeks, I was 100% sure of the dates but all through my pregnancy the doctor kept telling me I was only 7 weeks (even though I had been going to the clinic since I was 6 weeks pregnant due to type 1 diabetes) I’m so confused, I feel like I just need some answers and the doctors won’t give me any! I’m angry and confused and feel like I need answers to be able to move on