I feel the same!!!
I worry about it most days now actually, I have had this strange feeling since the beginning that my dates were out by a month as I thought the period I had was just implantation bleeding as it was a few days late and what not....
Now it is December 5, which would be a month early, and I am wondering more and more... I am sure it's nothing and my dates are all perfectly fine for January. It is just something I got in my head and now the time is here, I think about it way to much.
Don't mind me, I'm just pregnant and silly sometimes ( I can use that right!!!)
Scans show otherwise so I am sure I am just being difficult.....