I have been trying to use menstrual cups. I want to know how safe they are? It is generally said that air circulation around vagina is very important to keep it infection free. But while using menstrual cup we completely block the vagina. Is it safe? Another major problem for me is, my menstrual cup enters the vagina successfully( it is little painful) but it does not open up. Why is it happening so? I would want to mention that I am a virgin. Please suggest me which menstrual cups in the are the safest and some tips on how to use it.