Achilies Tendon

I don't know what I did but my left leg started hurting. I think I figured out it's my achilies tendon. It hurts when I walk but I can run fine. To me that is weird. I am always careful about stretching when I am done running. It could be the Chicometrics video I'm using or a pair of boots I wore that have a 2" heal though I don't wear them everyday.  Anyone else had Achilis Tendon problems? It's hard because I can't take Ibuprofen because I had gastric bypass. I know to stretch but thought someone might have some insight for me. Thanks, Diona