For those who want to use the natural family planning method to conceive (which I recommend because it’s when you have intercourse not how much that matters) and also in case nobody ever informed you when a woman can and statistically cannot get pregnant.
Hint, an egg needs to be released in order for the sperm to fertilize it and this does not occur on the last day of a woman’s period. It occurs typically between day 11-21. Defining pregnancy on days 4-8 is not the statistical mean. I’d have to perform t-tests but I’m not sure day 4 even falls within one standard deviation of the norm.
And yes, some women have 3 day periods, others have 7 day. We’re not all the same!!