Terminated for taking medical days...

I'm sorry this is so long, but I feel I must explain the whole situation in order to make my point..

I started work as an admin assistant a month ago. I was just over four months along in my pregnancy at the time. My boss was very understanding the first week, when I had a lot of swelling starting in my feet and legs, and agreed to keep me as a part time employee for a while. She was very happy, as I completed more work in four hours a day than most other employees finished all day.

Anyhow, just last week, I got a nasty cold, and needed to take a couple days off work. My boss understood yet again, and told me to take care of myself and my baby, as that was the most important thing. I went to the doctor on Wednesday, and although she didn't seem too concerned, said I could take Thursday and Friday off to rest if need be. So I did. I also took some Zyrtec, which dehydrated me, although I didn't realize it. I started cramping on Friday, and spotted blood clear through til Monday. My husband made me go to the hospital to get checked out, and left a message for my boss two hours before my shift.

At the hospital, I learned about the dehydration, and that it was responsible for my cramping and old blood spotting, and also for the new case of Braxton Hicks contractions that really freaked me out.. I was discharged from the hospital Monday evening, and my boss called to check on me. She told me she got my husband's message and hoped I knew she was not the type of person to fire me over something like this, and to let her know if I needed another day off.

The next morning, after no sleep the previous night, 2 gallons of water and 12 trips to the bathroom, I was utterly exhausted, so I called to take one final day off. My boss called me that evening (yesterday) to let me know she had decided she needed someone in the office more often and I was being let go. She totally switched gears in the last 24 hours!

My problem with this is that although I had only been with the company 27 days( before I got sick), and I had the misfortune of getting sick during my first month of work, every day I missed was excused by my midwife or the hospital and were completely legitimate!! Was it legal for my boss to fire me? Is there some legal action in the state of Colorado that I can take? Punitive damages? Anything?? Please help!