Assalamu alaikum.Allah instructs to wait for 4 months and 10 days Iddah period for a wife whose husband died. But today we can know before 2 months whether pregnancy have occured. So why did Allah ask to wait for more than 4 months?Is there any other reason?Thank you.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

The wisdom of legislating the waiting period of a woman whose husband died is not only restricted to making sure that the womb is free [that the woman is not pregnant]. The scholars stated much wisdom, some of which is mentioned in Fatwa 85417, so please refer to it.

Moreover, the waiting period is an act of worship so one should abide by what is legislated about it in the Islamic Law.

Allaah Knows best.