If you are menstruating, there are certain poses that are not suitable to please consult the teacher before the class begins. The teacher may give you some alternative postures to perform during the class. Yoga teaches you about yourself . And in learning about yourself, you learn to deal with difficulties. Advise your teacher of your concerns before class.
Yoga is open to all people of all ages and levels of physical condition.
Do not be put off from trying a yoga class because you feel that you are too old, too stiff, too fat, too thin, too tired, etc. Yoga is a process-oriented activity with something to offer everyone.