How big is it? Did it create a web around it? Depending on how big the ding is, an autoglass repair shop should be able to fix it for you within a few hours/day. Maybe even take it to one of those places and see what they say about it.
If it didn't go through your windshield, I'd say the windshield did it's job. No windshield will bounce off rocks flying at excessive speeds without cracking....unless you pay for it.
If it didn't go through your windshield, I'd say the windshield did it's job. No windshield will bounce off rocks flying at excessive speeds without cracking....unless you pay for it.