Confidence Interval Question

I am practicing counting cards in blackjack on my own. The rules that I am playing, I have discovered that the house advantage is 1.97%. However, by counting and changing betting strategy, I am trying to determine if what I am practicing is actually giving ME the advantage in the long run. Therefore I wanted to create a 95% CI to determine if I do have the advantage. My statistics are a bit rusty, so I wanted to know exactly how I could go about doing this.

My plan is to go through the shoe and record my winnings/losses each round. Eventually I will have a mean/standard deviation. How will I set up whether or not I have the advantage? If you would like to use numbers as examples, I will just create some data. Sample size: 100 Mean Winnings: +4.8521 S. Dev.: 9.432

Thanks in advance for any help you can give. You can explain in advanced terms, as at one point I was very familiar with all of the terms/formulas.