All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions
The Iddah period for the divorced woman after being engaged in sexual intercourse (If she has a regular period) is three menstrual cycles not three months for Allah, The Exalted Said (What means): "Women who are divorced shall wait, keeping themselves apart, three (monthly) courses." [Al-Baqara/228]. In this regard, it is stated in Article (135) of the Jordanian Civil Status Law what follows: " The Iddah period of a married woman with a sound marriage contract, the one divorced from her husband after being engaged in a sexual intercourse and the dissolution of marriage according to the ruling of the Sharia's Judge: is three menstrual cycles provided that she isn't pregnant nor reached the age of menopause."
Further, the previous article states that if the husband departed from his wife while the latter is ritually pure, then her Iddah period will end at the end of her third menstrual cycle; her Iddah period will be three menstrual cycles. Besides, if the divorce took place during woman's menstrual cycle, then the menstrual cycle during which divorce occurred won't count, rather she is obliged to start over for new three menstrual cycles.
In conclusion, outlining three month as mentioned in the aforementioned article: implies that the occurrence of three menstrual cycles won't be taken into judge's consideration save after the end three months, because menses period differs from one woman to another, but if she claimed that she passed three menstrual cycles within less than three month, then it will be accepted so long an oath was taken by her before the Sharia judge. And Allah Knows Best.