Chest pains/upper-back pains. Cause?

I've been experiencing chest pains recently. It's like right on the chest bone in the very center of my chest (not my boobs just the chest). And my upper back has been hurting as well.

I work a desk job and I'm sitting with probably not the best posture all day every day. I have to lean forward a lot.

What could be the cause of this? I'm only 18 so I wouldn't say it's something serious. I've been to a doctor for them before and he just said anxiety or growing pains but that was awhile ago. I am a very anxious person especially recently so it could make sense.

Any thoughts? Should I visit a chiropractor?