No, it isn't. "Rogers et al. (1991) recorded the responses of 26 free-ranging black bears (Ursus americanus) to used tampons from 26 women and the responses of 20 free ranging black bears to four menstruating women at different days of their flow. Menstrual odors were essentially ignored by black bears of all sex and age classes. In an extensive review of black bear attacks across North America, no instances of black bears attacking or being attracted to menstruating women was found (Cramond 1981, Herrero 1985, Rogers et al. 1991)."