The maximum days of menstruation (Haydh) or (Hayz) period is ten days and the minimum is three days.
If the bleeding continues more that ten days, then any day after the tenth day of menstruation will be Estihaadha and Not Haydh.
Estihaadha is three types according to the amount of blood :
Qaleela (Little) (Blood does not fill the pad.
Motawasita (Medium)(Blood fills the pad but does not leak out of it)
Katheera (Big) (Blood fills the pad and leaks out of it.
In Estihaadha (Qaleela) she must pray and fast like usual but with one Wudhu for every Prayer if the blood is in small amount which does not full the pad.
(Motawassita) :If the blood fills he whole pad but does not leak out, then she has to add one Ghusl before Morning Prayers.
(Katheera): If he blood fills the pad and leaks out, then three added Ghusls will be obligatory, one before Morning Prayer, second before Zohr Prayers, and third before Maghrib Prayers.