I get a sharp pain on my right side when i release pee pressure. only at the beginning i get the pain. what could it be?

See answer: The pain only occurring at the beginning of urination makes a bladder infection less likely(the pain usually is at the end of urinating) and the right sided pain also suggests another diagnosis. One possibility is Interstitial Cystitis. If the symptoms come with your period Endometriosis involving the bladder is possible. See your PCP for a more specific diagnosis. You may need an ultrasound.