Confused!

[Saleenaoden]

I'm new to pregnancy, and I just went to my first appointment for my ultrasound. My baby measures 10 weeks. So, does that mean I conceived 10 weeks ago, or what does that mean?

It means you conceived about 8 week's ago. The date is based on the number of weeks from the first day of your last period...if you were having periods and if your cycle was 28 days exactly. So we say 10 week's pregnant but you weren't actually pregnant for the first 2 weeks...
The pregnancy app I use gives you an estimated conception date based on your due date.
It is confusing though....