Schedueling and Weekends

So I'm a new nurse. I have been off orientation for a week and, aside from freaking out on occasion, I'm starting to hang in there. My issue is the scheduleing on my floor. Upon hire I was told that I was going to work every 3rd weekend. After I got off orientation my schedule showed that I was working every other weekend. I was shocked and a bit aggrivated, but equired about it to the charge nurse that does the schedule and my floor manager. The both told me that they were hoping that they would be able to let everyone work every third weekend, they think they might have enough people to do it now, but they have to ask the older nurses if they want to work every 3rd weekend first. All new nurses will still continue to work every other weekend. Okay so this I didn't get told upon hire and it's a little schetchy if you ask me because I've met several nurses who have been employed there for years and they work evey other weekend, but my preceptor, who has only worked there a year and happens to be good friends with the charge nurse that does the scheduling, works every third weekend or less.

Now here comes the wammy. Since I am new and didn't want to rock the boat to much I decided not to put up much of a fight about having to work every other weekend. I wished to give them the benifit of the doubt and say that I misunderstood something upon hire. However, I just worked this past weekend and next weekend they have me working on Sunday, but the following weekend I'm off. I'm ******. I called my manager to let her know about my schedule because the charge nurse that does the schedule is off for a week. My manager starts to spew some bullcrap about how the hospital is a 24hr/7day a week instution and all shifts must be adequatly covered. I am not retartded. I worked as a registrar, secretary, and student nurse for a different hospital for 4 years! I've worked nights, I've worked evenings, I've worked days, I've worked every other weekend, I've worked weekend option, I've worked every 3rd weekend. The thing ALL of my jobs all they way back to highschool (which is like 7 different work environments all the way down to being a janitor and working at Subway) is that people had a regular weekend schedule. My manager is trying to justify scheduling me wherever the hell she wants and I think that she is wrong. This is only the second hospital I've worked for, and I realize that most 12hr shift schedules vary during the week, but do nurses normally have varying weekend schedules also?

My other issue is that the schedule does not come out at a regular time. Like at my last place of employment...actually at most places I've been employed...the new schedule was always sent out at the same time. Like if the schdule was only for two weeks the new schedule would be posted the Thrusday before the end of the old schedule or a six week schedule might come out 10 days prior to the end of the old schedule. This place doesn't have that. They also don't have rules about writing out forms for trading days or written ways to put in requests for vacations or a time limit that vacation quests need to be submitted prior to taking the requested days off. Is it wrong for me not to find this all very aggrivating and suspecious?