Depends on question
If a woman has a menstrual period
once a month, during 11 months of the year, but has 2 menstrual periods during one month each year, that is a normal pattern.
It means her cycle length is 28 days (13 periods a year). However, if she has a period twice in one month, once a year with no periods during the other 11 months, that would be unusual, and she should be evaluated by her doctor(s).