period problem!!??? stressing to much?

I recently started a pill for my adhd and before that I had no problems with my period. This month I've been eating bad, changing sleeping patterns,doing alot  of active things in the heat, stressed, and tried the new pill. 
My period is now 2 days late starting tomorow and usually I'm on time. I've had cramps, constipation, white discharge, and sore muscle joints but no period.
Can all these symptoms delay my period? Or can it be pregnancy?