When to start?

I was on implannon for a year.. But the side effects were too much, so I took it off.. Today I went to my doctor and she gave me a prescription for Yaz(24/4) (pills) to help me stabilize my hormones and stop the side effects once and for all. But she gave 2 options: wait till my period starts (I'm irregular) or start right away, do you think there would be any major difference? I want to start ASAP since my hair is falling like crazy 😱