Anyone else's hair straighten after 4-5 days of washing?

My hair are extremely CURLY and frizzy/dull and rough after wash for 3-4 days. I hate it.

Then after 5-6 days of wash (and not combing it), my hair starts shining a bit and magically straightens out a little with pretty spiral curls at bottom. The hair texture becomes wavy. I love my hair at this stage ! But unfortunately right when i start liking my hair i have to wash again.

So anyone know why this is happening? And what i can do so they become wavy right after inital wash?