We have a trip to Paris and London planned from April 1st-9th, and I've been reading up on traveling when pregnant. Most importantly, I've been trying to determine any risks that would make it a bad idea.
Much of the information I have found is about travel during the second and third trimesters, and the info on the first trimester is brief. One thing I've learned is to steer clear of any discussion forums where regular people post advice. This stuff isn't reliable and only confuses and worries. I read on one of these and radiation at high altitudes can cause harm during the first trimester when lots of development is taking place. I didn't see this anywhere else, but it scared me a little. I will be 7 weeks when we travel, a time when the nervous system and brain are forming.
I called my doctor and spoke to the nurse, who assured me that it should be fine for me to travel. Unless I have bleeding between now and then, they would have no problem with me going to Europe. She stressed the need to stay hydrated and to move around every 60-90 minutes, to use the bathroom often and to rest during the trip as much as I need. Now is not the time to be a marathon traveler and to force as many activities in as possible.
I feel much better about taking the trip now.