We can have blips in our period where it acts weird, comes heavy and then light or is not on our regular schedule. Your trip could indeed be involved. However, you haven't had a pap in a really long time so my advice is to go ahead and get yourself in for that. They can check you for pregnancy to rule it out. But try not to worry. Abnormal bleeding in a young woman is rarely anything to be concerned about. Do have your pap though. Let us know. good luck