I woke up about 4am with sharp pain in my chest , towards the left side and a tugging sensation that worsened when i breathed, also my left arm was numb, i put it down to indigestion as i had a bit of heartburn before i went to bed, but when i led on my left the pain worsened, when i woke up i was on my back, what could it be? do you think it could of been indigestion, i am a 37 year old female.