Symbolism, and the menstrual cycle?

You're already headed in the wrong direction, entirely. Art isn't about themes or symbolism, no matter how many people try to tell you otherwise. Art is a form of expression of the human condition. It serves to inform our senses and emotions, rendering us sensitive to and aware of new feelings and the often otherwise indescribable complexities of humans. Anything else is crude and barbaric. Let go of concepts.