Thanks for the advice. I got up today to walk, but decided not to risk it. I work in a very long building, so during a break I walked the whole building and back - about 1.25 miles - and didn't feel pain, so tonight I went to the gym.
I decided to get on the elliptical for half an hour because I didn't think that would bother my leg, and it didn't. But boy was I tired! Then I tried the treadmill on a very slow speed and tiny incline and did ok. So hopefully things are ok.
I am going to rest tomorrow, since it's my usual rest day. I will try walking again on Friday morning. No walking trails in my neighborhood. My block is perfect for walking, but it is on a concrete surface. I am also on a hill and have the option of doing some hill walking, but worry about going down the hill because I think downhill is what has affected my leg.
I read about shin splints and wasn't sure if that's what it was because the pain wasn't in my shin area but lower - a couple of inches above the ankle. But as I said, I'm no doctor!
Thanks for the encouragement. Exercising really is what drives my weight loss and being "good" about not overeating, so it's important that I am able to exercise regularly.