just wondering...how old r u? but, i dunno how true this is but i'll let u know anyway, if u started ur periods less than 2 years ago they r still regulating n stuff n missing a few periods isn't that uncommon, also if u have a change of diet, ur body has stress (even if mentally u dont feel it), if u lose or put on weight, if uv been very ill..all these things can disturb periods, so it could be one of these things.
if it was me, i'd take another preg test in a couple of weeks, if it still says negetive, then i'd say u definately weren't. if ur still having doubts then go to the dr's n have a blood test, that way it'll be definate answers.
good luck xx
