Advice pls

I woke you to call from my job that I am Fired. What should I do?
I stared working there on 01/16 full time,  I am currently 31 week pregnant. On 10/05/16 I end up in the hospital and was there for 2 week as they baby was pushing to get here. I was only 20 weeks them, I had short cervix so my OBGYN pull me out of work and been in bed rest since them. Do to my condition, I can return to work until I have the baby. Multiple documents has been provided to my employer and I was collecting disability as is part of my benefit at work. So they call me today and told me they have decide to let me go and wish me best luck. How can they do that to me. I feel so broken, stress and I don't know what to do. I'm in the state of VA and advice pls?