Depressed/Job Advice?

Kim
So I worked at my job for 4 1/2 years then found out I was pregnant and they made me switch departments. I've been in the new department for 4 1/2 months and no one at my old department bothers asking about me (including the department head who was fairly new at the time). 
You just figure when you give so much into your job they'd treat you better. I don't know how I'm going to go back after my pregnancy knowing they dont care. We have volunteers and one got pregnant and they kept up with every step of the way, threw a baby shower, ect. Just makes me really upset and I'm not sure what to do. Is it selfish to be upset? 
I've tried looking into other jobs but there's nothing around with the pay I make.