Is it normal to get your period in the beginning & the end of the month??

Happens once a year?: A woman with cycles shorter than 29 days (shorter than a 30-day or 31-day calendar month) will likely have 1 ovulation per month during 11 months of the year, but have 2 ovulations during one month of the year (since she has about 13 cycles a year). Thus, she will have two periods during one of the months in a year, in order to fit 13 periods into one year.