Air Travel

Is it safe to travel about 4 hours in an airplane while 34 weeks pregnant? It's really strange circumstances, I am literally between doctors right now so I do not currently, and very temporarily, do not have a doctor to ask this question to. I have had a doctor up until the recent move, and was in the process of getting one the past few days, but now am having to move back and my flight is in the morning. They aren't open at night either so I have no one to call. This is an emergency and I have to go. My body has been through a lot of bending and packing and carrying stuff the past few weeks, so I think I can handle the stress of being in a high altitude, I've just never flown before and don't know what to expect. I have nausea pills also.