Hi, Isis

It is unusual to improve that much in 2 days - but the good news is, you went up, not down!

Chances are that one of the tests was a little bit of a fluke - sometimes you basically get lucky and get lots of questions that are easier for you and sometimes you get unlucky and get lots of questions that are harder for you. (This can happen on test day too - fortunately or unfortunately, depending.) It might be that you basically got a little unlucky with the first and a little lucky with the second and you're really somewhere in between.

I'd go look at the individual questions you got right and wrong and see what you can learn about your strengths and weaknesses. This analysis might help you to figure out why you had such a big different in the scores - though, really, the bigger issue is just to keep improving! And for that, you want to look at all of the questions and learn at least one thing from every single one.

Just be careful not to spend so much time taking practice tests that you don't have enough time to do lots of learning in between! Good luck!