I was moving some pots around that have been sitting out all winter and after lifting one (with a plant in it) off of an upturned pot, I found these worms underneath. They are writhing around in the water collected there and when I moved one out of the water, it quickly scooted back to the water.

They are between an inch and inch and a half long. My initial searches online made me think maybe they are pot worms, but the info I've found led me to think maybe they're a little big for pot worms. The pot with the plant that I lifted off the top does not have holes in the bottom, so I don't believe that they came out of the dirt in that pot.

Any thoughts on what it might be? Is it something I should be concerned about? This is a new house to us, so I'm just getting into cleaning up a garden area and thinking about soil amendment.