Should I do this ?

I'd say yes. If your employeer thought you were not a good fit, they would tell you so. This is what probationary periods are for, to see if the job seems like a good fit for everyone concerned.

I agree with travel50,

but your statement alone says it all; "I just started orientation for a new job I have had some reservations about, but I need a job."

I have been there, and done that! I say secure your next job and bow out of the first, just try not to burn your bridges on the way out, a lot is to be said about tact. If you can get out of your first job without looking like your a flake, you might just find yourself back there again down the road - remember, it's a small world in nursing. And just because you may never go back to the same place, you might just run into that person you ****** off jumping ship at another, more desirable location with less successful results. Good luck, ttdr