Funstruating
A word you at the very most once in a man's lifetime. The term is used when a woman is actually enjoyable to be around, even though she is having her period. Symptoms may include, but aren't limited to: acting more like a guy, huge appetite, very chill, open to conversation about anything. (This all sounds like the exact opposite of woman having her period, but it is possible).
...Holy crap... you're... you're funstruating.