Tried to exercise

I tried to exercise tonight.* I went to my NIA (dance, martial arts- fusion) class.It was so hard.  I took it easy.  I didn't do much at all.  But my chest hurt.And then I felt queasy.I had to leave class. My husband is a sweetie and reminded me that I was in the hospital *last week.*He reminded me to listen to my body and take it easy.  This was a small clot and I don't feel very sick, just a little tired.I'm disappointed.I guess I just need to be patient...     *My doc said I could exercise, if I didn't over-exert myself