I agree it is possible that these symptoms could be in your head, but for my first two pg (3rd a m/c), I had them as early as you. Breasts enlarged immed.- more than usu. P/d size, extreme tiredness, diff. Abd. Symptoms, some dizziness/headaches, breast tenderness, slight constant nausea, etc. I wasnt ready for them, so I tried to convince myself it *was* all in my head!
Oh, and there was a "sense" of it too- tho I ignored that too!
Just never know, until you find out for sure.
M r