What should be the time spacing between laser sessions?

I have only just had my first session on my face and body. It took more than 5 weeks for my facial hair to grow back, I just had it treated. Now I'm in my 7th week and there is no sign of hair growth on my legs, little started to grow on my arms. What should the time spacing be ? And how many sessions do you think I'm going to need? PS: I have black hair/fair skin, middle eastern background.