Why would you have two periods in one month?

It is not common to have two periods in one month. However, there are a few reasons why this might happen:

1. Hormonal Imbalance: A sudden change in hormone levels can cause an additional period. This can occur due to factors like stress, thyroid issues, or Polycystic Ovary Syndrome (PCOS).

2. Implantation Bleeding: Sometimes, a fertilized egg can implant into the uterine wall a few days before the expected menstrual period. This implantation can cause light bleeding or spotting, which may be mistaken for a period.

3. Medication or Treatment: Certain medications, such as those used for hormone replacement therapy or emergency contraception, can affect menstrual cycles and lead to additional bleeding.

4. Uterine Abnormalities: Structural abnormalities in the uterus, such as fibroids or polyps, can cause irregular bleeding patterns and lead to an extra period.

5. Infection or Illness: In rare cases, an infection or an underlying illness can disrupt the menstrual cycle and result in additional bleeding.

If you experience two periods in one month, it's important to consult with a healthcare professional to rule out any underlying medical conditions and determine the cause.