I'm going into gr. 7 and I need some help with some 'girl' things?

Okay I'm going into grade 7 and I just started my period 2 days ago. Where should I keep my pads and stuff so that when I have to go change a pad it doesn't seem so obvious? And when's the best time to change my pad? (during cl, between cles or during recess)? PLEASE HELP!?!?