Hi, it took me 10 months to get pregnant and so I was taking tests every month, anyway when it finally came up positive and the doctor confirmed it I didn't feel any different at all, so I questioned it too. I only felt a little bit more tired than usual and that was it. The 'last period' thing is just a guideline, I was told to give or take a week or two. This was explained to me when I was questioning why they let you go over two weeks after you are 'due' and thats the answer I got.

Hope it makes sense...

congratulations and hopefully you will miss out on the morning sickness symptoms like I did as well