Menstrual Cramps
I (Ana) am sorry to hear you are suffering from menstrual cramps. I understand your situation completely because I have suffered from them too! You should of course keep up your regular yoga practice and the raspberry tea is a great idea as well. You might try adding a well balanced magnesium/calcium/vitamin d supplement. Even a slight imbalance or deficiency in any of these minerals can cause cramping.
Megafood makes a wonderful one called "BONE." Make sure you get the newest formulation which is even better than their original. Take two 3 times a day with food. It might take up to a month to start feeling full results.
Do you get clots? A friend of mine does and takes baby aspirin a couple days prior to and during her period and it has helped her have easier periods with less cramping. She is an herbalist but feels the baby aspirin works well for her!
Overall, for menstrual cramps, we recommend our Yoga Bliss Hips DVD as well as the Positive PMS segment on Yoga Quick FIxes.