This pain your have described, which is there for a week, does NOT appear to be related to a heart condition. Also you are young, previously evaluated and there are no major risk factors. With the available information its almost certain that there in no heart condition involved.
What exactly causes the pain should be found, Yes there could be an anxiety component to it. May be you can try some over the counter pain reliever and see if the pain goes away. If the pain is worrying you much , you can get an ECG done, which practically rules out any heart related problems.
Hope this helps. Thank you.