Denied a promotion because I'm PREGNANT!

There are several departments at my job and last night I found out from another department head that the promotion one girl was given was supposed to be mine. The reason I ended up not getting it is because I'm 8 months pregnant and he doesn't know what will happen after I have baby, like if I will come back.

Mind you, we close from January 1st to February 1st and my due date is December 31st! I plan on working until labor so it's not like I won't be there to fulfill the job as I will be back 2 weeks after we reopen give or take a week depending on when baby actually makes her arrival!

This is not the first time I've been treated unfairly at this job while pregnant.

Should I say something or not? I don't want the other department head to get in trouble.