It started about a week ago, just noticed it in the shower, doesn't hurt or itch.
It doesn't always itch. It certainly looks like ringworm. Anybody can get it since the fungus is so common and contagious. Just use an antifungal cream such as Lotrimin and follow the instructions exactly and for as long as recommended.
Please save yourself the embarrasment from improper diagnosement on something you have no idea about =D