Menstruation normally lasts 3-7 days. Menstruation that lasts 1-2 days is not normal (hypomenorrhea). Irregular cycles and hypomenorrhea could be due to a disturbance in the axis hypothalamus-pituitary-ovaries. That disturbance combined with being overweight could indicate Poly-cystic ovarian syndrome (PCOS).
You may want to consult your gynecologist about this.