What Causes Delay In Menstruation After Taking SMZ-TMP For Bladder Infection?

I had a bladder infection . I went to the doctor and he prescribed me sulfamethoxazole-tmp. It's almost 2 months now that I've had a missed peroid since I take the medication . I took home pregnancy test and also I went to the hospital to take one and they all came back negative. My peroid still has yet to come on today. do you think it's the medication that's delaying my cycle?