ok, so if you have a brain you fuck her 5 days in a row when she's most fertile. That still leaves 360 days a year not to fuck.
Actually, a woman can have sex any day of the year she pleases. If you think penetrative sex is the only form of sex then you're wrong, as is your estimate above too.
For pregnancy, the fertile days are crucial, but, there are many factors which affect whether fertilisation occurs, and more importantly whether the gamete produced by the union of the sperm and egg develops normally. For some unknown reason, the fertilised egg may not divide normally, and then the pregnancy fails.
Other factors depend on whether the acidity of the route the sperm takes is enough to kill the sperm. Smoking, drinking and other vices of the chemical kind may affect reproduction.
Sometimes, ovulation may not occur, either through stress in the daily life the hormones may not have stimulated egg production. Or, if egg production occurs, there is a blocked fallopian tube. Maybe, eggs cannot develop due to cysts in the ovaries. The chances of pregnancy is highest for the younger women, and as time passes, those women who delay their first child will see a diminished chance of concieving naturally. The reason is, that a woman is born with a set number of eggs in her ovaries. With each period she has throughout her life, the numbers reduce, and aren't replenished. She is, to use an unfortunate similie, a reproductive timebomb. Once the onset of the menopause is upon her, she will have hormonal changes and she won't be able to concieve anymore. That's why you don't see grannies getting pregnant very often unless assisted in some way.
I think you should value a woman's input into the discussion, since they will know more about when they can have sex more than me.