This is also quite frequent in third world Muslim (and some non-Muslim) countires, where men will often accuse their wives of adultery, and the village idiots will get ready for the stoning.
A man I know got married and had sexual intercourse with his wife. He then went on a journey and while he was on the journey, she completed a menstrual cycle. Later, when he returned home from the journey, he found out that she was pregnant. He now doubts who is responsible for the pregnancy. What should be done?
He should not fall into any suspicion. He should not be in doubt of his wife’s modesty without having clear evidence.
The blood seen by his wife could either have been menstrual blood or blood from a broken blood vessel. I believe that his wife got pregnant from him. It is not at all uncommon for a woman to continue to have normal menstrual cycles during the early stages of pregnancy. This is something well known both to women and doctors.
It is unjust for him to accuse his wife of something she did not do. Suspicion can never be used to accuse an innocent person. He should fear Allah and safeguard his wife. He should strive to uphold and defend her honor and dignity and refrain from levelling any baseless accusations.
And Allah knows best.