Stress effects our moods by changing our attitudes and our thinking. Someone could be happy one minute and have a disagreement with a friend the next minute and end up very hurt or disappointed.
Any stress to the body (ie illness) can cause delayed menstruation or a completely missed period for that month. It can also make it arrive early. If you miss two periods in a row, you should go and...
In sports of any nature you must remain focused and maintain a calm so that you react effectively to changes around you. Stress heightens some reaction times but can block clarity of thinking