Paying attention to the upcoming points might help you reach the answer you are looking for:

The six types of women in haydh:

Mubtadi’ah: A woman who sees blood for the first time in her life.[1]

Muztaribah: A woman who has seen blood for a few months but has not formed a habit or whose former habit has been disturbed and has not formed a new one.[2]

Nasiyah[3]: A woman who has forgotten her habit.[4] (For instance, there are high chances that a pregnant woman or a woman breast-feeding her child who hasn’t been on a period for more than two years will forget her habit.)

Waqtiyyah and Adadiyyah (a woman having the habit of time and duration): A woman who sees blood in each of the two consecutive months at a particular time and for a fixed number of days. (For example, in each month she sees blood from the 1st up to the 7th of the month.)

Waqtiyyah only (a woman having the habit of time): A woman who sees blood in each of the two consecutive months at a particular time but the number of days varies. (For example, in two consecutive months, her blood starts coming on the 1st of the month but she becomes clean on the 7th day in the first month and on the 8th day in the second month.)

Adadiyyah only (a woman having the habit of duration): A woman who sees blood in each of the two consecutive months for a particular number of days but the time of commencement is not the same. (For example, in the first month the blood is seen from the 5th to the 10th of the month and in the second month from the 12th to the 17th of that month.)

How to find out which blood is haydh in the end of one’s cycle (when the blood has stopped before ten days):

If the blood stops before ten days, all of it is haydh, making no difference between the six types of women mentioned above. Of course, women with a specific habit have to do istizhar (will be explained) if the blood they see exceeds their habit and that is because they don’t know if the blood will go on to break the ten day mark or not. (For example, if a woman’s habit is 7 days, and she sees blood for 7 days and the blood continues afterwards, she has to do istizhar for the remaining 3 days before the ten day mark.)[5]

Ruling: Istizhar means for a woman to consider herself ha’idh (on her period) and observe the rulings pertaining to ha’idh women (to refrain from worship and stay away from the acts that have become haram for her as a result of haydh) until things clear up (meaning that she has to wait and see if the blood exceeds ten days or not and in this time period she can’t pray or fast at all and has to refrain from the acts that are haram for ha’idhs). Of course, for women whose period is always the same number of days each cycle, it is haram to do istizhar (meaning that they have to only consider number of their habit as haydh, even though they aren’t sure if the blood will go on to exceed ten days or not).[6]

Of course there are different viewpoints on the amount and how long istizhar can be done and what amount is permissible.[7]

The ha’idh’s duty after her blood stops before ten days:

When the blood stops before ten days, different cases are possible.[8] The ruling on each case is mentioned below:

1) She knows that she has become clean of all blood, even on the inside. This case is once again divided into four cases:

a) She knows that she will see blood again before the ten days are over: Some

marjas such as Imam Khomeini and Ayatollahs: Khu’i, Araki, and Fazel say that the days in between are also considered part of the haydh period. Others such as Ayatullahs: Golpaygani, Sistani, and Makarem believe that they have to do ihtiyat (meaning that they have to observe both the rulings pertaining to clean women whose haydh has ended and the rulings pertaining to those who are still on their period, and in other words, they have to both perform ghusl and pray [and fast during the holy month of Ramadan] and refrain from the acts that are haram for women during their period) in the days inbetween that they are clean in.

b) She knows that she won’t see blood in the days to come before ten days are over: She is clean and as a result has to perform her ghusl and start her prayers.

c) There is a probability that she will see blood again: She has to perform her ghusl and start her prayers.

d) Her habit has always been to see blood again before the finish of ten days: Imam Khomeini: As an obligatory precaution, she has to observe both the rulings of a woman whose period has ended and has become clean of blood, and the rulings of one who is on her period (meaning that she has to both do ghusl and pray, yet still refrain from those acts that are haram for a woman on her period).

Ayatullah Sistani: If the habit of her always seeing blood again before the ten days are over, causes her to be sure that she will see it again, then it is obligatory for her to observe both the rulings of a clean woman and the rulings of a woman on her period. Others such as Ayatullahs: Khu’i and Araki: If this matter causes them to be sure that they will see blood once again before the ten days are over, they are considered ha’idh and have to observe the rulings pertaining to haydh.

2) She isn’t sure if the blood has completely stopped or not. In this case, she has to examine herself. After examining:

a) She finds herself clean: Like the previous case in ruling.

b) She sees blood: Two cases:

1) She has a regular habit: Three cases:

a) She is sure that the blood will stop before ten days are over: She                            has to wait for the blood to stop.

b) She is sure that the blood will pass the ten day mark: The amount that is equal to her habit is haydh and the rest of the days she sees blood are classified as istihadha.

c) She isn’t sure if the blood will pass ten days or not: She must do istizhar.

2) She doesn’t have a regular habit: She has to wait until the blood stops (of course till ten days). Here, one must note that:

a) In order to examine to see if her haydh has ended completely or not, after her bleeding has stopped, she must insert a cotton ball in the opening of her vulva and leave it there for a few moments and after pulling it out, see if it has been stained with blood or not. If it isn’t, she is clean and her haydh has ended.[9]

b) If she prays before examining herself, her prayer is void even if she later finds out that she had been clean before praying, unless she has been able to have the intention of getting close to Allah (qurbah) while praying although she wasn’t acting according to what Islam had wanted from her.[10]

For more information, see:

1- Tawdih-ul-Masa’ele Maraje’, v.1, pg. 252-295.

2- Ahkame-Banovan, Mohammad Vahidi, pg. 67-90.