It certainly wouldn't hurt to have it checked out (if for no other reason than to put your mind at ease), but PVC's are really common. I have SVT and excessive PVC's, and I've been on a beta blocker for years, mostly just for my comfort. I've also been told by my doc that most people have them, and for most, they aren't serious.
I also think that our pain and discomfort cause us to focus more on our bodies, so we tend to notice more when something is a little off. Most people probably have PVC's, but many probably don't notice them. Some things that trigger PVC's are caffeine, stress, alcohol, tobacco, and not getting enough sleep.
Amorvida, I also get them at night. Something about lying on my back seems to trigger them. Weird.
If you are having any other symptoms such as dizziness, feeling lightheaded, shortness of breath, etc., it probably would be a good idea to see your doc.
Hugs - Austen