Hi!
Acid reflux can cause heart burns—you can feel something hot coming up or get intermittent stabbing chest pains. However, all chest pains at any age should be investigated by a doctor, especially for heart attack/angina.
Take antacid gel and proton pump inhibitor like omeprazole. Avoid spicy food, fuzzy drinks, alcohol and smoking (this you already have).
Please consult your doctor regarding this. Hope this helps. Take care!
The medical advice given should not be considered a substitute for medical care provided by a doctor who can examine you. The advice may not be completely correct for you as the doctor cannot examine you and does not know your complete medical history. Hence this reply to your post should only be considered as a guiding line and you must consult your doctor at the earliest for your medical problem.
At your young age I think a spontaneous blood clot is unlikely.
Have you had any damaging physical impacts, fall, hit or run into by something? I have known, as a person your age, of foot ball players getting a blood clot from foot ball (tackling) injuries. That's why I ask the above.
The doctor's advice to see your doctor is the best advice. But try to limit your input to your doctor to your symptoms, not to self/web diagnosis which can detract from the value of you input. That said a physical injury is not a self diagnosis, is it part of symptom/environmental input.