They ‘may’ or ‘may not be ‘coming
You can never tell when period will arrive
Your raw ingredients to make the blood flow well are sometimes there, and often not.
Low Yang Qi to make Blood and to hold it where it should be.
Check out what you make your Blood (and thus hormones) with.
Esp fat protein and Iodine
For this you need a calm, peaceful life and habits, especially great resources (nutrient dense food and a great digestive/metabolic system).