You are experiencing 'palpitations', which basically mean you are aware of your own heart beat. Generally this is normal, especially after being physically active.
If lucozade is an energy drink, and contains caffeine, then yes, a lot of caffeine can induce palpitations. I find it unlikely that you have chronic high blood pressure
if you are only 13. If you were experiencing a migraine
, it would be very obvious; I don't think this is what you are suffering from. However, we on this forum are not in any position to diagnose you; if you really feel concerned about your this, you should see your family doctor.