Confusion about my due date 😥

I went and recieved my ultra sound about two weeks ago at my gynecologist office (which I was really excited about) I thought that I was only eight weeks but when I did the ultrasound they told me that I was 10 weeks and 1 day and my due date was Nov 2nd.. Towards the end of the appointment they told me I needed to come back in about two weeks so after waiting two weeks, I went to my appointment and the midwife I saw proceeded to tell me that I was barely 10 weeks and my due date was November 10th now?? Her reasoning behind this was that when I first came in I gave a rough guesstimate of the date of my last period So she was using that date and she wasn't going to change my due date... I thought the whole reasoning of getting an ultrasound was to get a more accurate due date and check on the baby?? Has this happened to any of you guys?