Switched birth control, weird period..women w/experience or ideas?

I switched my birth control pills after last period(yasmin to yaz). My periods always starts on Friday for yasmin, but it was scheduled to start this Wednesday for yaz. It didn't come Wed or Thurs, but it came today(Friday), as if my body is still use to the yasmin. The thing is that its just brown..or maroon color, not normal red color, and it's not heavy, and I'm having no cramps what so ever. Thursday late at night I had brown discharge too. Do you think it's the switching pills that my body is just trying to get use to or can I be pregnant? We had 3 times this past month with the pull out method-which I know don't work, but we decided to do it anyway-. Please answer if you have any idea or past experience with any of this. Thanks! Oh and I am scheduled for a gyno appointment next week, but I'd like some input before then thanks!