I am 19 years old my heart pains sometimes a lot mostly 4 or 5 times in a month for 2 to 3 minutes. I had a test ECG but Dr. suggest not to worry. What should I do now.

If your Ecg is normal then it's not a heart problem. In most probability it must be gas / acidity or muscular pain . Whenever you have the pain try to drink a glass of lukewarm water and walk around.... it will relieve your pain if acidity. Drink plenty of water daily about 2 liters. Apply some pain relief gel like volini and use hot water bag on it. If the problem still persists please take proper treatment. Also do not stress much ....excessive stress can lead to acidity which can also give you severe chest pain .

You may be having gastritis, are you not eating your meals at proper intervals. Eat bland and home cooked food and remain calm. U have already consulted cardiologist but get one 2d echo done.