"play wheels on the bus and get the hell out of my sight"

driving to work this morning, i passed a school bus. a stopped school bus. it had its red flashers on and stop sign out. yes i am a rebel without a cause. actually the bus was off the road. there's this pre-school that has a semi-circle for a driveway and the bus pulls in to stop at the front door of the school. it had it's flashers on dropping off kids, but it was a good 20 foot off the road. do i stop?? what are the regulating legislative details in regards to this example?? i figured the law said, "Slow to 5mph, look around for police officers, look at the bus for childen and squeek by", so that's what i did.