I really wouldn't sweat it, especially if you've already done your Pre-OCS physical (that's MEPS, right?). I had a friend who did his Pre-com w/ me. In perfect health, but when he took physicals, he gets high blood pressure due to nerves. He got through it, but if you create problems out of nothing, it can be worse.
Also, keep in mind that just because you "fail" a "test," doesn't mean you're out. You can retake it. Sometimes things just go screwy. Don't always take a no at face value...a lot of times it's because people are lazy and just don't want to figure out what has really happened (and that's certainly not specific to physicals). I remember when I was in high school, I was 14 out of 250 (or something), but I was also in a magnet program, so I was 8 out of 40. I got turned down for my NROTC scholarship because 8/40 was outside the normal window. I called back and simply asked a question. Low and behold, when they heard the other number, I fit w/in their acceptance window.