It's been a very long time since I've started b/c but I believe my doctor said 2 weeks to a full month. I wasn't sexually active and didn't have a partner so the waiting was no biggie. Since, I've been on so many different brands I've lost count.
I HATED Yaz towards the end. It seriously screwed with my system. Moods and physically. Without going into gross TMI I nearly had my cervix shortened due to an allergic reaction to that medication. The doctor wasn't sure WHY my body was reacting in such a manner as she had never seen such a reaction so she didn't link it to the pill. Thankfully I switch b/c before I went through the surgery. That was an embarrassing mess.
I'm currently on the nuva ring and short of getting an IUD put in, I love it.