What's this silverfish-like bathroom bug?

I was using my boyfriend's bathroom in his old Capitol Hill studio when I discovered these small silver bugs gliding across the floor as though they were swimming. My first instinct was they were silverfish... then I looked it up and they did not look like the pictures. They were smaller, more rounded and soft looking. I could not see their legs nor did I see any antennae. I think they really hate light because in the seconds I walked to get my boyfriend one had hidden and the other stopped moving to save itself. Since we have not seen them but I would like to know what they are in case they come back. This may or may not be linked to them but my boyfriend was adding soil to his plants in the tub earlier that day.