Earlier this evening, I went on wikipedia to do some physics homework. I clicked the 'search' button, only to find no articles matched my search. So? There was a message on the webpage, saying I had a new user talk message, displaying my IP. I clicked on it, and it said that I had vandalised an article, to be specific, 'Erection'.

This is weird. I have never been on that article, and I have never edited anything on wikipedia. In addition, I have a basic firewall protection.
Should I be worried? Please help me.