I don't know what cord resistance is, but please, please try not to worry. If there is anything you can do, the doctor will tell you. In the mean time try to relax. Read a book, watch a movie, get plenty of rest, drink water, etc. Try not to think about it too much.
Did your OB mention the possibility of delivering her early? If your OB has not mentioned it, then I wouldn't spend much time thinking about it. At 33 weeks it's certainly not ideal, but babies have been born at 33 weeks. Every week that you stay pregnant (every day, in fact) will give your baby a better start. At some point the doctor may believe that the baby will do better outside the womb than inside. If that is what your OB recommends, then that might really be what's best.
Again, try not to worry too much. Ask your doctor lots of questions. Do not be afraid to ask. Make sure you understand what the concerns are and what it is that he/she recommends and why. Knowledge is power. Keep asking questions.