The female body is beautifully complex. Inside this beautiful body, there is a thin tissue located at the opening of the vagina known as hymen. Everybody is different and so is the tissue. Some bodies have extremely small tissues that it seems like they do not even have a hymen.
Due to the climatic conditions winter wet/humid days are generally bacterial favourable conditions. Menstrual cups prevent most of the bacterial build ups keeping the vaginal area dry and causing very less or no infections probably.