Question about being reallocated

Hello all.

I am looking for some general information about your experiences and/or your facilities policy of reallocating nursing staff. I am a new grad RN (that's about all that's new about this 40 some-odd-year old gal). I have been working on my unit for 2 months, and tonight I was told I would possibly be re-allocated to another unit because someone mis-counted the RNs on schedule for tonight's shift (but they weren't sure if there were any units that were short). Our unit had an unwritten rule that new grad employees were out of the re-allocation cycle for their first 6 months of employment, but this was informal, and is now not followed. I barely feel comfortable on my home unit much less being sent off to the great beyond with no clue of the possible acuity and procedures on another floor. I was offered the opportunity to work another day this week that my unit was short, in lieu of being reallocated on this occasion. What say ye? Does your facility have a minimum time period before reallocating new grads? Or does anything go? Thanks.