Fatwa ID: 01520
Answered by Mufti Mohammed Tosir Miah
Question:
Question on Periods:
Nov: from the 9th for about 7 days Dec: 8th (eve) to the 15th (not sure of time) then again on 30th at about 7pm and continued till 2nd January Jan: pure for 10 days and bleeding reoccurred on 13th and is still continuing
Q2: If a woman had sexual intercourse and before she could have her ghusl for janabah she started her haidh, can she delay her ghusl till she is paak? Similarly if a husband had intercourse with his wife during her menses (haram) does she need to take ghusl for that?
Answer:
In the name of Allah, the most Beneficent, the most Merciful.
There are two principles which govern the rules of menstruation and post natal bleeding.
The first principle is that the Prophet of Allah 
said, “Two menstruations cannot occur within fifteen days of each other.” (Sunan Baihaqi)
The second is that if a Mutadah bleeds for more than three days but less than her normal habit, this lower number will become her new habit for the next period. Her present period will be deemed as ended when the bleeding stops, not until when the habit would have ended. (Key to Purity p.20 –p.21 & Dars Tirmizi p.363 v.1)
Keeping the aforementioned information in mind we can derive that the bleeding from the 30th December to January 2nd would be considered as haidh and as there was no gap of 15 days, the bleeding on 13th January would be considered as Istihadah.
Finally, regarding your second question the wife in both the situations can delay her ghusl until her periods finish.
Only Allah Knows Best
Mohammed Tosir Miah
Darul Ifta Birmingham.
