Recent onset of chest pain, left sided near sternum.?

Last week my husband and I went to disneyland. The second day of being at the park, my chest started to hurt when we started making out 10 minute walk to the park, and then periodically throughout the day, would hurt while i was walking felt better when i sat). I thought maybe I was dehydrated. Drank tons of water. We have no been home for almost a week, and had been fine until today. It came on very suddenly, but was the same pain I felt at disneyland. Ive been drinking a lot of water today, so I dont think im dehydrated. I was sitting, and the pain was sharp, mild to moderate (more nerve wrecking then anything extremely painful) and hurt when i was inhale about half way. I went and took a hot bath, helped some. I then laid down... when im laying, it doesnt hurt at all, but when i stood up to get dressed, the pain instantly came back. Its very localized, in a spot about the size of a quater, and hurts when i stand, pick things up, or bend certain ways, as well as inhale when im in a sitting or standing position. I was thinking maybe the roller coasters at the park bruised my chest muscles or something, but not sure. Any ideeas? Please dont just say "go to the doctor" thats not what im looking for.