All you ladies know what I’m talking about, the natural cycle that occurs for a woman every month.
Students always ask, “Can we practice yoga during our period?” The answer is, it all depends on your body.
1. Do you have the strength to do the regular Led Ashtanga Vinyasa Yoga (the class I usually teach)? If yes, then go to the next question… If no, stay at home and rest. 
Listen to your body.
2. Is your flow heavy? If yes, practice relaxed and restorative yoga. This means if the class is our usual Led Ashtanga Vinyasa Yoga, opt to stay home. If the class is a restorative yoga class or a moon series yoga class, you may still attend. If your answer is No, you can attend the class and jump to question 3.
3. Are you still bleeding? Have you ever done yoga and your period stopped? If your answer is yes to any of the two questions, i usually advice students to take it easy and replace their closing series (due to all the inversions) with Viparita Karani Asana (Legs up the wall pose). If your answer is no to both questions, then feel free to go on with the regular closing series but be mindful of what your body is telling you.
The book “Nawa Yogini Tantra” has an informative section about this. Actually I highly recommend that book to women who are practicing yoga. Since this book is not easy to get a hold of here in the Philippines, you can read up on other articles regarding yoga and menstruation through the articles listed below. I don’t want to sound like a pro (which I’m not) by simply enumerating different scientific reasons why and why not. 
What I do know is that we should listen to what our bodies are telling us…
Yoga Journal: Inversions and Menstruation
Yoga and Menstruation, Questions Answered by Geeta S. Iyengar
A woman’s Balance: Inversions and Menstruation by Mary P. Schatz, MD
Conclusion: LISTEN TO OUR BODY…
Namaste.
- Karen