What Causes Long Menstrual Cycle After Hitting Lower Back,knees And Head?

I fell down 14 stairs a week ago, I hit my head, lower back knees and every other part of my body I suffered several severe bruises exspecially on my lower back. I went to see my PCP he says i have bruised my kidneys and wanted to check to see if there was urine in my specimen, however when I landed i instantly began bleeding. My PCP and myself thought it my be my menstraul cycle however its been 13 days and I have never lasted over 7..I am very concerned any suggestions?