On average… 4.3weeks On average… 40weeks On average… 9.3months And the factor in that that 40 weeks is calculated from the date of last period, so on average 2 weeks where the woman is not *actually* pregnant. So 38weeks or 8.83months. I win.

Pregnancy is 10 lunar months for humans. Our reproductive cycle works on a lunar month (4 weeks)

Pregnancy weeks are calculated on the last period date. Pregnancy months since when you are actually pregnant (a bit later)