Browse 390+ woman calendar period stock videos and clips available to use in your projects, or start a new search to explore more stock footage and b-roll video clips. Close up of female hand writing ...

The calendar method helps you predict your fertile days by tracking the length of your menstrual cycles over several months. Please enter your age and the first day of your last period for more ...

The college football early signing period starts this week. Here's what you need to know about it, including dates and ...

The Mayan calendar’s 819-day cycle has confounded scholars for decades, but recent research shows how it matches up to planetary cycles over a 45-year span. That’s a much broader view of the tricky ...