hell Mrs julieworrall
first you have not clarified that the pain was on the right side of your chest or on the left side of your chest but regarding you querry about cardiac problem i may assume it as on left side of the chest.
to reach the cause of the pain your experiencing i would be requesting you for certain information i.e.
1. does the pain starts at rest or after some sort of exertion??
2. do you have any chronic problem like hypertension
or acid peptic disease?
3. how was the nature of the pain?
4. is it associated with food intake?
5. how it relieves?
after knowing replies for the mentioned questions it would be easy to resolve your queries. still if you have all investigations declared clear then you must perform echocardiograph and exercise tolerance test that is performed from cardiology clinic. if still there is no significant findings on them then there is no serious problem and your problem can be labeled as ACS.
thanks with regard