well its kind of hard to really say all i can give you are facts based on what i know from going to school for nursing, and i know the sperm can live up to 3 days inside a womans body. it i not necessarily true that you can only get pregnant one day per month. your body has a cycle as we all know. there are a few days actually that we ccan expectto ovulate either before or after our period,(depending on the female). and during our period it is also possible to become pregnant. with the sperm still living 3 days after you had sex, you have to determine your cycle and when you oovulate iit is .
This depends on her menstrual periods. If she has regular periods it is hard for her to get pregnant. But, in case she has irregular periods she may get pregnant. There are women who got pregnant the day before their periods and others the day after periods.
Pretty much the same as any other day, unless you have your cycle down to a fine science, which none of us do. Well, not most of us. You don't know when you ovulate so therefore you have NO idea WHICH day or days you can become pregnant or which days are more likely. You can get pregnant ON your period so the day before doesn't seem much safer.