I Am Experiencing Pain When Pressing In On My Left

I am experiencing pain when pressing in on my left side or slightly in front. If I tighten my stomach muscles it protects the "tender" spot. this location is above my navel on my side. Well below the spleen. not just discomfort this is pain. Never had this symptom before. Bowell movements are normal. curious what could this be. Today is the beginning of the 3rd consecutive day, seems it may be slightly worse. On set was quick but is now the same.