The contract states the probationary period may be extended to 40 days being the other 10 days are used for classroom training. Artcile 4, Section 1, Western Supplement
This time of year is quite hectic for your mgt team and they may have lost track of how many days you have worked. You could end up qualifying by default.
At my Center they can and usually do, a 10 day extension. I just finished day 39 yesterday. I had today off because once you work day 40 you're in, so I have my graduation call scheduled for tomorrow. Everybody gets a 10 day extension at my Center because they can't keep up with the paperwork of the new hires.