Menstruation
The uterus then starts preparing for another ovum. For most people, the time between their periods is about one month. For about 2 years after menstruation starts, the time between periods is not always the same. Some menstruators may skip a month, or have 2 periods close to each other. It is also possible and normal (within reasonable limits) to have cramps (rather painful squeezing feelings) or to feel bloated (swollen up) in the abdomen at periods.