What Causes Pelvic Pain And Swollen Vagina Inspite Of Being On Birth Control Pills?

I have bleed black stringy blood, after the thick black stringy blood came what looked like quarter sized clots and Dust like particles,from start to finish on my period. Had a constant itch to the point where i couldn t move and pelvic pain and swollen vagina on my last periof. My latest period i had dark red and black blood and still thick stringy black blood, and dust particles. It seemed i passed what looked like s whole bunch of thick string clot like bloid really fast the sixe if a quarter and period nly lasted 4 days. This all started 2 months after taking birthcontrol pill. Idk if that is causing this the sumpyoms on the oackage did not list these.. Im just scared, i dont know whats going on and no doc so far can figure out and keeps rfering me to ther people..