This is the second pireod (of about an hour) that i've had pain in my left side. what should i do?

Although there are: many potential causes for chest pain you have not provided enough information to allow a more narrowed diagnosis. Not even knowing your age makes it impossible to know if this is something serious or not. I think you should go to a healthcare facility as soon as possible and get checked out. If it is a heart attack you have already waited too long but they might be able to prevent further harm.