(jackson here btw) I just went through this a few months ago. What you need to do it put a voltmeter across your battery terminals while the car is running. I cannot remember what the actual range of values are ( I think it is like 13-14V but it could be 12.5-14V) but I can look them up before tonight. The voltage should be fairly constant. If it is not, then the likelyhood of your alternator or voltage regulator being bad is high. Give that the regulator is inside or a part of the alternator, you will be changing it either way. This is where I would start.
Are you coming to the show and do you have a voltmeter? Let me know if you do not and I will bring one with me. I will prolly be a little late but I will show. Gotta give you the bra and all.