your medical card is not the best example to follow, since the information on it was encoded in a specific format for your healthcare system.
I suggest you to encode a simple sample card like:
Track 1 - Kevin
Track 2 - 12345
Track 3 - 67890
After that read it on your magnetic reader to notepad and see what you get, it will be easier for you to understand what you get if you previously know what you have encoded in the card.