Can a chain on a chain saw "stretch"?

I have a Stihl "farm boss" chain saw with about 40 hours on it. I keep it sharpened, replaced the plug once, and especially like the auto lube feature so I don't have to think about oiling the chain. The last few times I have cut with it, I've needed to tighten the chain after 10 - 15 minutes of use. The last time I took it apart and saw that there was no more room for adjustment. Is it possible to take out a link to shorten it, or do I just need to break down and get a new chain. Money is tight, and I am cheap, but I do need to get this running again.