I experienced a sudden onset of bad left side chest pain which spread down my left arm?

Early this morning at about 3am I experienced a sudden onset of bad left side chest pain which spread down my left arm and a bit in my back. The pain was at it’s worst for about an hour, but stayed to a lesser extent for the rest of the night. There is a family history of heart disease (I have not been genetically tested for the condition yet but will be in the next couple of months) so I went to A&E this morning. They did and ECG which came back normal so they then did a chest X-Ray which also came back looking fine. After this I was told to go home and manage the pain myself. No bloods were taken. Unfortunately the pain hasn’t sopped and I still have it now- it feels almost like a bruising pain that comes and goes. If I breathe in very deeply and hold my breath, the pain gets worse and it sometimes gets worse when I move around or press on my chest. Despite having good ECG and X-Ray results, because the area I am feeling pain in is a potentially serious area I am still quite worried about it. Since bloods and further testing was not done, I am worried something has been missed. I am a 22 year old female. If the pain still persists for the next few days, how long do you think I should wait before returning to A&E?

Age: 22
Female
Medications: contraceptive pill
Yes
General Information: ā€“ I have fainted in the past before and as a result I am getting gentic testing for a heart condition, I thought my pain might be heart related hence why I went to A&E bute since ECG came up normal they didn’t do other testings.