Since the PCV valve is probably the cheapest part on your car, I would suggest just going ahead and changing it yourself. It should take you longer to open the PCV valve package than it does to actually remove the old one and plug in the new one.
If you don't want to do it yourself, then have this done at the next oil change.
I strongly suggest that you avoid quick lube places if you value your car.
The percentage of expensive screw-ups at these places is--distressingly high.
Your oil change regimen sounds okay, overall.
With your type of driving, 3k miles sounds a bit early.
On the other hand, I never suggest going 7k miles.
Since 5k miles is really easy to remember, I suggest that you change the oil every 5k miles, but be sure that you personally check the oil every week. If the rate of oil consumption was to suddenly increase, you could wind up damaging the engine if you don't check the oil weekly.