If you can, see if you can get them rubbed out by an athletic trainer. Of course, it's only two days before, and you don't want to be sore for your meet, so if you get them rubbed out don't get it done too hard. If you can't get that done somewhere, then try stretching them a bit, or using a running stick. Don't stretch too hard, though, you don't want to pull something.
Good luck, maybe you'll wake up in the morning and they'll be all better.
1. stretch in any free time you have
2. ice massage (freeze ice in a paper cup then masages your calves with it)
3. tiger balm, or icy hot works well to losen muscles
I had the same problem a couple weeks ago. My calves and the area below were so tight they couldn't be rubbed out. I talked to a friend of mine and she said needed to drink more water and use a foam roller. It worked great! I use the foam roller before and after my runs and I haven't had any problems since.
I get tight calves sometimes and I still find the best thing is stretching them out on the stairs or any other raised surfaces with something to help you keep your balance, I like running sticks and foam rollers too - make sure to keep hydrated and apply heating and cooling creams if necessary.