Massallah pertaining to haiz and istihatha

Asalamualykum…i have a problem with my haiz it has become irregular after having a baby…i get my haiz nw about after every ten days and it lasts for more than 3 days…i would like to know when do i take it as haiz and when as istihadha? Eg. I bled the 1st of september for 7days than after 12days i bled again which lasted for 5days than after 10days i bled again for 7days…thz type of cycle continues so i dont have a minimum 15 day tuhur period so what do i do?i am confused and dont know when to perform salaah and when not to…i hope i have been clear in asking my question jzk for your efforts