It sucks to get injured while sleeping. If there's one activity that should be safe, it's sleeping!

Last year, I slept on my arm wrong and woke up with a sore shoulder. I thought it was no big deal, just a little sore, so I rode as usual. Over the following week, the pain got worse and worse. After 2 weeks, I couldn't ride anymore and went to the doctor. Ended up having to rest for 4 weeks. This was mid-June to mid-July, so the waiting was absolute torture. Don't mean to depress you, I hope your calf is nothing like that!