Washing jeans at work unprofessional?

I had my monthly really badly and had to use my jobs washing machine (it's in the basement) to wash my pants...they ended up firing me, stating it was misconduct. Was it? I was the only one on shift and I had pajama pants in my trunk that I just threw on...no one really noticed except for the lady leaving shift, and she told my boss she saw me leaving the basement with a "bag". My employer umed it was food from our food pantry...I am so humiliated, but I've decided to fight this one with the unemployment board. Should I even bother?