Why after u have been regular with ur perid do u become irregular?

Why after u have been regular with ur perid do u become irregular?
im really not sure maybe stress or something its weird
Could be stress related or illness...sometimes a change in diet or medications will do it.
I would say talk to your doctor ASAP. Its definitely a sign that something is going on and you will need to be evaluated just in case.
stress, pregnancy, medicine, pco, and a number of other things
stress and illness can do that
your hormones are out of balance, see a gyn, maybe get on birth control
simple, your cycle is changing, and does it every so often. nothing to worry about.