I have been a cross country runner for a little more than 3 years now, and I am 17 years old.

I was out running last Friday. During a pick-up, I felt a very large strain in my chest, as if I had pulled something. However, the pain persisted and felt like a weight on my chest. I feared I was having a heart attack. However, my heart beat subsided but the pain did not.

In the next three days, inhaling and exhaling fully was painful. I initially also noticed some palpitations.

Now, a little more than a week after the initial incident, I still have pain under my left chest near my sternum when I exhale fully.

Also when I bend over I feel a squishy sensation under my sternum. I also feel this sensation when I jog. In addition, I feel bloated after meals and pass gas more often than before.

It seems I most likely have a hiatal hernia from what I read online. Are there any other possibilities for what I have? I have a doctor's appointment on Monday, but any advice/suggestion is very welcome. I really want to get back to training for cross country.