Traveling with baby

My fiance and I are taking a trip out to our family back in California in March for two weeks, and I'm worried it's going to mess up our sons sleeping schedule (By then, he will be four months). We're in Maryland so we're three hours ahead and, while his schedule isn't exactly set, he's still sleeping through most of the night, usually from around 10 or 11 to around 5 or 6. Any suggestions or advice? Should I be worried? I didn't think this was something to talk to his doctor about so I figured I'd hopefully reach someone who has gone through the experience.