I guess it would depend on when you are due. We had a girl in Nac1 who was pregnant and due in late November. She induced over the Thanksgiving break so as not to interfere with classes. You won't get a break from your clinical rotations. If you miss you will have to reschedule with your instructor to do one-on-one and that can be hard because the unit also has to be available when you need to reschedule, and several other nursing schools do clinicals at all the hospitals.
IMHO, I would think that you would be OK up to about 6mos gestation, then your body would get tired with all the additional stresses from school and studying and late nights, etc. Are you already pregnant or wanting to get there this semester? Do you have other children? Do you have infant care set up for when you are in school? These are all things to consider.