I might sound stupid but I’m a tad confused

Chantel

I know when my last period was (1st October 2022) I took my iud out at the very end of that period was still having the brown before it ends

So I ovulated on the 16th I felt it or thought I did I got pregnant but when I had my dating scan on the 30th baby is 3 days ahead of what I thought so my due date changed from 7th July to the 4th July

My question is then did I ovulate earlier than I thought? Or is baby just measuring bigger?