there are many reasons for menstrual irregularities like,
- presence of poly cystic ovarian syndrome: characterized by irregular periods
-increased stress and strain: can lead to hormonal
changes affecting hypothalamo-pitutary axis leading to irregular periods.
-change in nutritional status leading to anemia etc.
-usage of contraceptive
pills recently can also affect menstrual cycle.
now you wait for next month periods if same irregularity gets repeated visit local gynecologist and get examined.