Have thought about this for a while ...
right in new moon bella spills a tiny drop of blood from her finger and jasper goes INSANE. Now jasper and all the other cullens go to a high school with humans, how come when girls are on their periods they dont go mad to kill them, esp edward and bella???

also how come the cullens cant just store blood (like with renesmee in BD) and have it like a bottle of water they can take to school and drink if temptation is too much???