Periods for the first few years will be very unexpectable, basically it's never right on time and you'll have a lot of spotting, where you have a little blood at random times of the month but it's not you getting your period. Sometimes you'll skip two months or have two periods in the same month. It's not abnormal, it's like this for almost everyone who gets periods, just make sure you always have quality pads/tampons on you and a fresh pair of underwear. Also try and get liners (there basically just really thin pads with no wings or anything) for when you're spotting, so you won't have to keep changing your underwear.
