Answered by Ustadha Shazia Ahmad
I normally have my period for four days. On the fourth day I normally bleed at night but am clean the next day. If I refrained from prayers of `isha and tarawih thinking that previously this is how my cycle works, but the next day I find that I was wrong should I make up those prayers I missed?
If you woke up on the fifth day and realized that your period ended the night before, then it is obligatory for you to make up your isha prayer and sunna to make up your tarawih prayers.
It is wrong to act according to your previous cycle. If your period is the same every month, you still can not act according to habit and just stop praying. You must act according to what you see. This means that you must physically check to see if your period has ended, not merely assume that it is over. One my teachers recommends that ladies check if their periods are over about a half hour before the end of the prayer’s time. This way, they have sufficient time to make a ghusl and pray.
And Allah knows best.
Shazia