It's normal for menstrual cycles to vary, especially during the first few years after starting your period. Irregularities in the cycle, including changes in duration and flow, are common as your body adjusts to hormonal changes.

However, if your period only lasts for an hour, stops, and then starts again later for another hour, it may be a sign of a hormonal imbalance or other underlying health issue. In such cases, it's a good idea to seek medical advice to determine if there's an underlying issue that needs attention.

Talking to a healthcare provider can help you understand what's happening with your cycle and whether any further evaluation or treatment is necessary. They can also provide guidance on what to expect and how to manage your menstrual cycle as it continues to change over time.