I want to get reply to some my question. 1- Can we have intercourse if my wife is in her period but the bleeding has stopped on the 4th day of her cycle? 2- What should a woman do if she is having problem of vaginal discharge all the time? Can she pray salat, fast or read Quran?

Praise be to Allah, the Lord of the Worlds; and may His blessings and peace be upon our Prophet Muhammad and upon all his Family and Companions.

If the menstruating woman becomes pure and the menses stops completely even after a day of menstruation then her husband can make sex with her after she takes a ritual bath. Know that the purity from the menses is known by two things 1) dryness of the vagina and 2) the cleanness of the sanitary napkin.
If she is still bleeding or she is still having the yellowish or muddy discharge before the end of her period or she became pure but still did not take the ritual bath, in all the above conditions making sex with her is forbidden. So, whoever did so should make repentance and should give a Dinar or half Dinar in charity. One Dinar is equal to four and one fourth of gram of gold.
2- If the vaginal discharge continues and does not stop for a period that is sufficient to make ablution and perform prayer then the ruling of such a woman is just like the woman who has a continuous reason of impurity. Therefore, she should wash the place of impurity, apply some absorbents, should make Wudu for every prayer after entering its fixed time and then should perform the obligatory prayers and voluntary prayers as much as she likes. The Wudu does not break even if the discharge comes out during the prayer.
However, she has to renew her Wudu for every obligatory prayer after its fixed time begins.
The woman who suffers from the prolonged flow of bleeding can combine two prayers and then she can perform both of them by only one Wudu. Know that if the discharge stops for a period that is sufficient for making Wudu and performing prayer then she should wait till that period to perform the prayer. If she fears that the fixed time of any prayer ends then she should act as mentioned above. She should do the same for touching the Qur'an. But, purity is not compulsory for fasting and reciting the Qur'an without touching it. Therefore, a woman who is in her prolonged flow of bleeding should fast unless she starts menstruating or has post childbirth bleeding.
Allah knows best.