If you don't have a period and you are premenopausal then your focus should be to restore your fifth vital sign i.e. your menstrual cycle. If you haven't had a period in more than 3 months, then chances are that you need to increase your calorie intake around your training to meet the energy demands of your sport. Research has shown that exercise stress in the absence of adequate calorie intake can increase risk of menstrual irregularities.
Consider your energy intake before and after training, just as your warm-up or cool down. Keeping yourself in an energy sufficient state especially around training can help you get your period back, while also improving your performance.