Vulva pain even during my period.

I get labia majora pain almost all the time for the last 5 years. I’m not really sure what’s causing it. But I’m guessing it’s because of my pelvic floor disorder. Tight pelvic floor. I heard that the pelvic floor lessons during your period. Or something like that. So why do I still have vulva pain on my period? There is no skin problem. It looks normal. And there are no infections in vagina.