How many days was your monthly period for?
When was the date you first started this continuous bleeding?
For example your bleeding started on 1st of January and previously your haydh used to go on for 7 days (for example). Therefore on the 1st of January for 7 days you will take as haydh and 23 days istihadha to complete a total of 30 days. When the 30 days are up, again 7 days haydh, 23 days istihadha and so on and so forth.
Note: To determine the number of days that will be regarded as haydh in your current bleeding, you can look at the number of days the women in your family get their haydh and if that is not orderly, look at the number of days that the Hadith has outlined for haydh. The Hadith says any number of days between 3-10 as long as it's closest to your natural cycle. Therefore for example your natural cycle was between 7-8 days, you can choose 7 as the number of days of haydh and if for example your natural cycle was approximately 10 days, you can select 10 as your number of days for haydh in the current bleeding.