My question involves labor and employment law for the state of: Indiana

About a month ago I was told by my employer that I would be receiving a promotion to a teacher leader. At that time, he also stated that a co-worker had applied and that she would also be promoted. I was not at that point aware that the other teacher had even applied for the position. This was all said in front of several co-workers.
I congratulated the other teacher and she hadn't even heard that she was promoted, in fact she has yet to hear from him at all.
After a few weeks, he had not spoke to me further regarding this position, so I e-mailed him. He told me that we were both going to have to interview for the positions and that due to a third candidate applying he realized that now he only needed to promote one teacher. I'm not sure if this is illegal (verbal contract) or just unethical.

Also, although at the time he knew that I am pregnant, we have since discovered that I am having twins and I wonder if that is changing his answer.