Help me figure this out.

🔸My last period was 8/4

🔸I got my BFP 9/8

🔸estimated due date was 5/12

🔸I got my first ultrasound 9/30 and I was told my due date is now May 23.

How is that possible? My cycles are usually 29 days in length. If I would of ovulated to be due 5/23, I must of found out I was pregnant like 2 weeks??? Totally not possible. ??!

What’s going on?