Like satya said, day one is the first day of full bleeding before midday.

Generally (not always) the cervix dips down when AF is near, but then I got a positive this cycle and my cervix was quite low, so I don't think cervix position tells you anthing other than when you are ovulating.

My SIL never got a positive pregnancy test for her first pregnancy, they just didn't work for her, only a BT could cofirm her pregnancy.

I would wait a week and see a dr if AF still hasn't arrived.

GL!