when missed period what does it mean ?

I've been always getting period cramps couple days before and this time I haven't even felt anything , my period is late what could this mean ? Yeah I know it could mean I'm pregnant but I don't want to get my hopes up .... could this just mean I'm stressed out or pregnant or I'm just going to get it the following week ? This has never happened to me before . If it means I'm pregnant has this ever happened to someone , I heard you sometimes you spot blood if pregnant .