My day was actually pretty good for the first time in about a week, until the end of the day at work. People have been SO rude because of me being on light duty. Not one bit understanding at all. So one of the ladies got a call from a coworker that works on the first floor and she wanted to know why I was on light duty, as if it's any of her business and wanted to know why I was still working there if I can't do everything. Of course I got upset and immediately called the Director of Nursing, left a message and eventually she called me back. Before I could even talk to her about what had happened she informed me that I cannot return to work until I get a release back to full duty. I'm pregnant...not diseased or dying! I don't understand how this is ok to do. I am very capable of doing my job, I saw every single one of my patients today and my immediate coworkers are willing to work with me and help me. I'm scared! I'm a single mom...meaning one income household. I'm going to the assistance office tomorrow after my ultrasound, still unsure if everything is ok with the baby. Now I get to worry about this too. I'm so worried I won't be able to get any assistance, or not enough. Does anyone know how that all works?

If I were you I would call her and try to set up an appointment to talk to her in person. It's really easy to "fire" someone over the phone because you don't have to actually see the look on their face and it's that easy to blow them off saying there's nothing they can do.
If you set up an appointment, you have an alloted time to express your concerns and feelings towards being underestemated.
Other then that I'm afraid after researching on the internet, a similar case whas brought up against american airlines and the pregnant woman lost the case because the light duty potentially offered to employees only applies to on the job injuries. Here is the web site if you would like a place to start yourself.

http://ppspublishers.com/articles/bulletin_pregnant_employee.htm

Sorry to hear about your job. If there is anyway that you could somehow tie your almost miscarrage to being work related you may have a shot, however this is just what I got off of an internet site designed to inform employers of what they can and cannot do. Please, for your own piece of mind, research this site and others relating to PDA (the pregnancy discrimination act). I am not a lawyer so If there are extenuating circumstances maybe you should try to contact one for info based on your specific circumstances. PM me if you need to talk to someone. I check in here at least once a day!

Another site....

http://www.afscme.org/wrkplace/wrfaq06.htm