Hi Since A Year I Am Experiencing Severe Pelvic Pain

Hi since a year I am experiencing severe pelvic pain with pain in lower back and thighs initially it arouse after 3 to 4 months but now I am experiencing it every month. pain is so severe that I had to take I/M pain killer and it lasts for 1 hour. since 3 months I am noticing the pain with hair dye. whenever I apply hair dye I experience it. does it has any relation with this or just a co incidence?