In tune with your body...

I was reading a post earlier about a woman saying she was in tune with her body and knew all the signs and symptoms she was having was pregnancy symptoms. She said she knew she was pregnant even before she took a test. Has anyone else felt like they knew they were pregnant even before you took a test? It's usually the opposite for me. If I think or feel pregnant then I'm not whereas if I don't think I am or aren't even thinking about it then I was pregnant.