1- Can we have intercourse if my wife is in her period but the bleeding has stoped on the 4th day of her cycle?2- What should a women do if she is having problem of vaginal dischanrge all the time? Can she pray salat, fast or read Quran? Please, tell what to do?

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.

When blood of a wife's monthly period comes to an end completely, she should make Ghusl (bath), and then, her husband can have sex with her, whether her monthly period lasted for the normal period of time or not.
Allah Says (interpretation of meaning): {They ask you concerning menstruation. Say: that is an Adha (a harmful thing for a husband to have a sexual intercourse with his wife while she is having her menses), therefore keep away from women during menses and go not unto them till they have purified (from menses and have taken a bath). And when they have purified themselves, then go in unto them as Allâh has ordained for you (go in unto them in any manner as long as it is in their vagina). …} [2: 222].
To make sure that monthly period comes to an end completely, a woman is advised to enter some cotton into her vagina and if she finds no trace of blood or something like that, this means she becomes pure.
For the other details please read the Fatwa:83621.
Allah knows best.