Piercing, sharp pain in heart

Hi everyone,

For the past couple of months i've been experiencing this piercing, sharp pain on the left side of my chest, under my left breast. It feels like my heart is majorly cramping up. I don't have any pain that radiates, no shortness of breath, & no dizziness. The first time it scared me to death, it kind of hurt to breath in, so i placed my right hand on my chest, leaned forward and waited for it to go away. The pain lasted about 5-10 seconds but it felt like an eternity. The next time it happened i just froze and held my breath. Its happened 4 or 5 times within 2 months. I am a 33 year old healthy female with no heart disease in my family. I do get heart palpitations though when i eat alot of chocolate or drink alot of caffeine. Is anyone else experiencing something like this? Thx.