Why is the Iddah of the widow is 4 months and 10 days?

  
Dear noble brothers, Allah, Exalted and Sublime be He, says in the Noble Quran:

(And those of you who die and leave wives behind them, they (the wives) shall wait (as regards their marriage) for four months and ten days…) 

[Al-Baqarah, 234]

What is the wisdom behind specifying this period to be 4 months and 10 days? Well, man may wonder why the Iddah (The observing period the widow spends after her husband without being allowed to get married until it ends) of the widow is specifically 4 months and 10 days. He may ask, "Why does Allah the Almighty not make this period four months, five months, six months, two months or three months?" 

Scientists of medicine say that pregnancy goes through three stages. The first stage is that of uncertainty, in which the menstruation ceases, which is a non-definitive sign of pregnancy, as there might be other causes, than pregnancy, for cessation of menstruation, such as psychological or hormone disorders or malfunction of the woman's reproductive system. In other words, cessation of menstruation is not a definitive sign of pregnancy.

The second stage is that of semi-certainty. At this stage, the woman undergoes feelings of depression, a tendency to be left alone, and other digestive symptoms, such as nausea and vomit, which are commonly called "symptoms of pregnancy", as they, most probably, indicate pregnancy. However, such symptoms are not a definitive sign of pregnancy, either, for they might be symptoms of pseudo-pregnancy.

Surprisingly, on the 126th day, i.e. on the tenth day after the passage of the four months of woman's Iddah that is mentioned in the Noble Quran, the embryo's heart begins beating, and the embryo begins moving. This is the third stage, which is the stage of certainty. Hence, the embryo's movement inside his mother's womb is a definitive sign of pregnancy. Allah the Almighty says: 

(And those of you who die and leave wives behind them, they (the wives) shall wait (as regards their marriage) for four months and ten days…) 

[Al-Baqarah, 234]

This Noble Quran is from the All-Knowing the All-Aware, and these pieces of information are written in books of medicine whose authors have no idea about this Ayah, and they have never read it, because they are not Arabs. Allah the Almighty says: 

(We will show them Our Signs in the universe, and in their ownselves,)

[Fussilat, 53]

Such definitive medical facts are translated into Arabic. Yet, amazingly, they accord with Allah's Divine Book!