I doubt it has to do with your period. I am more inclined to think that he is nervous about being out of his comfort zone and in a place with different people, sights, sounds, and smells. Dogs don't always do well with changes, and they may feel stressed. Some dogs are more sensitive to changes, and when they feel stressed, they are more likely to bite. Please be very careful. It may help to keep him confined in a quiet area and not let him be around people he is not comfortable around for the time being. Another possibility is that he is acting protective towards you. Regardless, make safety your top priority.