Yeh, that totally sucks! Get it looked at ASAP, a good glass place can do several things, (including replacement of course); either fill the crack, or even sand minor burrs down. Depending on the deductible, your insurance will take care of it & they don't count it as a claim against you.
If it ever is caused by debris kicked up from a truck, take note: I got the cab # of a rig that caused a break in mine a couple years back. I contacted them, & after filing a CHP report, they sent me a check. Still wasn't the same as the original windshield, though (moulding, etc.)
When I asked how/if this can be prevented in the future, I was told: "Don't Drive"!!
Anyway, sorry, I know how it feels- Any little imperfection on my perfect vehicle really p***** me off, but you know, stuff happens.