Q&A: Can you have two periods in one month?
I am trying to get pregnant. I had two periods last month—one at the beginning and another at the end. Does the second one count for the next month?
Women who are ovulating normally will typically have a cycle length from the beginning of one period until the beginning of another of between 26 and 30 days. The greater the deviation from this range, the more likely it is that a woman may not be ovulating or is ovulating infrequently or irregularly.
Since most months are 30 to 31 days in length, it is possible for a woman to have a period start at the beginning of the month (for example, January 1) and have another period towards the end of the month (for example, January 28). When timing when to have intercourse or when to start ovulation testing, you should always use the first day of your full flow as “Day 1″ rather than the actual calendar date.