What the heck is irregular periods really?

Timing or amount: "normal" periods occur every 28-30 days and last 3-5 days with "modest' bleeding. Periods are abnormal if they occur more frequently, infrequently (such as every 2-4 months), are excessively heavy. If periods require more than one pad or tampon per hour, or lead to fatigue or anemia, this is excessive bleeding. Periods 6 days or more are irregular.

Unpredictable period: Menstrual cycles are defined by their rhythmicity and predicability every 26 to 35 days normally. Irregular periods occur in between cycles, or are delayed and prolonged. Causes are many varied usually requiring a gyn visit.

Mixed signals: Irregular periods are caused when your body's signals for ovulation and menstruation get confused by hormonal imbalances that can be related to your thyroid (TSH), pituitary (LH/FSH/prolactin), ovaries (estrogen/progesterone). Many external factors can affect the hormones: malnutrition, stress, obesity, for example. Hormonal contraception can help to regulate your periods, which is healthier.