Indoor Pest Control - Pink worms in bathtub?

I'm wondering if anyone has come across thin, pink worms (about 1 - 2 inches in length) in the bathtub. I noticed the first one a few weeks ago and didn't pay much attention to it after I washed it down the drain. About every few days or so after the first sighting, I noticed one and again just washed it down the drain. After seeing a few of these worms, I became disgusted and bleached the entire bathroom. I thought that took care of them because I didn't see any worms for about a week after I bleached. Today, though, I saw another and it was a bit longer than the previous ones. I can't figure out where they're coming from.

I have a cat and a dog, but have not noticed any worms in their stool or bedding areas. Plus, I've only seen these worms in the bathtub. Any ideas on what they are and how to rid of them? I've searched the internet in vain. I appreciate any suggestions.