Earth moves yet again..

This time very close to home. 4 earthquakes in California in the past 5 days. That sounds a bit scary. Does this indicate a looming destructive earthquake ahead or just aftershocks? Interestingly, we are supposed to be living in a very scientifically advanced era but we still cannot predict such destructive forces of nature let alone prevent them. I am now closely following all the seismic activities around the world after the 2004 tsunami near Indonesia.
Every time I hear about an earthquake, my stomach churns a little. I don't know why. I have never experienced a serious earthquake before. I have heard about a lot. So this makes it even more intriguing. Hopefully there should not be any destructive one in the near future.