Severe bruise

I was tripped by my 85lb dog.  I fell on her and my left thigh went into a severe cramp.  I was unable to sit or stand for a few days because the cramp was so severe.  A week later, my thigh bruised from my upper back hip down to by knee.
Could this have been caused by the severe cramp, or is it possible something else happened when I fell?  
I have been to see my doctor, and she told me not to de any bending, squatting or pushing for at least 2-3 weeks.
The bruise has gotten better, but 3 weeks after the injury it is still sore and bruised.