This is great information if you know how long your period typically lasts, how many dags ago your last period was, how many days ago you had sex, when you last ovulated and whether sex happening mid cycle ovulation fertile time. A lot of this information I personally don't know, so this wouldn't work for me. However, if you meticulous about keeping track of this information it is a great pregnancy predictor.

Interesting resource helps you know the optimal time for pregnancy. Does require that you have a good knowledge of the dates of your menstrual cycle, sexual activity and ovulation.

I bit too much information to have to sort through to get an idea of whether or not you are pregnant. The information is interesting; however, I would much rather take a test at home or in the doctor's office instead of going through these various steps.