I was never told I was an "at will" employee at time of hire. I was there 3 weeks learning my job and doing quite well. Then one day suddenly I was told "it's not working out" after I was only there for three weeks. My supervisor actually emailed me and said she understood that they were teaching me too much in a short period of time, so she wanted the other girl to do certain job. This girl went on vacation and now she is back. She said things will be easier now and go at a steady pace. She also said not to look at this as a bad thing.