I know this is nasty and embarring,but boogers HELP!?

Well, I CAN NOT breathe through my mouth to save my life! I hate it,and I hate when people do it! (weird I KNOW) but how do i get rid of boogers throughout the day. I clean my nose in the morning and how do i know during cl when i have a booger? Whenever, i get the time I go to the bathroom but most of my teachers wont let me and I get embarred Im a girl and in 7th grade HELP!