Hey! Last December, That Is December 2015, I Had Intestinal

Hey! Last december, that is december 2015, I had intestinal obstruction and leparoscopy was done by my doctor and he took out the blocked part. Later that part was send for lab testing and nothing came out as such and no specific reason came out for obstruction. But my doctor said this happened because of intestinal TB and he started my TB treatment on 25 december. I took AKT 4 for 3 months and in april I started with AKT 3. The problem I am facing rightnow is that my periods have become delayed. Till april everything was fine but then my periods got delayed 3-4 days in may... 7-8 days in june.. 9-10 days in july and i haven't got my periods till now for the month of august and I am already 15 days late. Also my ultrasound was normal when I got checked for PCOS and I haven't been sexually active for last 2 months which means I am not pregnant also. So what can be wrond with me? I am 22 and have been exercising regulary also. Too worried what is wrong now.