totally agree with JoyRenee... talk to your Dr., make sure that they don't see any reason for you not to travel, and take copies of your medical records with you. Also... you may want to stake out the nearest hospital (if you are flying) or hospitals along the way (if you are driving) to your destination... just in case you have any surprises. Your Dr. may even be able to recommend another practitioner for you to see where you are going should you need to, that way if you have any concerns while you are away you can avoid a hospital all together.
My guess though is that everything will go very smoothly! I hope that you enjoy your trip!!
Most women talk to their doctor before they travel and get copies of their medical records to take with them. You're past the point of miscarriages. And being RH negative won't mean anything for traveling, especially if you already got the Rhogam shot.