The Shortest Period of Pregnancy is Six Months
Question :
I was away from my wife for a period of one year, and then I returned to her. 8 months and 25 days after I arrived, she gave birth. I have some doubts about the five days missing from the full nine months, so please advise me.
Answer:
One should not have doubts about his wife if she is pregnant for less than nine months before giving birth; the shortest period of pregnancy is six months. This is based Allah's saying:
"And the bearing of him and the weaning of him is thirty months."
And His saying:
"And his weaning is in two years."
This proves that the shortest period is six months, so if a woman gives birth in the seventh month or onward, there is no reason to doubt her.
And Allâh is the Grantor of success,
Source:
Ibn Baz
Fatawa Islamiyah, Vol. 8 Pages 393-394