If the download progress looks like it's starting over, then it probably is. In other words, a file failed to patch and wyUpdate is downloading the catch-all update. See: What's the "catch-all" update? Why is it so large? And why is it being downloaded?.
Also is there anyway to calculate the download speed so I can estimate the time it will take?
You can use the velocity of the progress change and make a rough estimate. See the ProgressChanged event.