I can't explain why this would have just recently started, but I don't think three miles is long enough for this to be a problem with lack of hand positions. It sounds like an issue with bike fit to me.
Have you raised your seat lately? What Hiroshima said about too much weight on your hands is right. If you raised your seat, you probably also need to raise the handlebars.
Bar ends could help makes this go away, but a bike fitting is probably a better way to fix it. Stronger abdominal muscles would probably help too.