The link of the site changes ??

I have been having a proplem several days , when i sign in , the site link suddenly change to [urlqq-sg.com[/url],
even thought i opened and checked several time the site link , but soon i sign in the site link changes and sometime it takes me a while to get to pindiy.com even though i keep writing it by myself so i can sing in <///3

hope someone help me with this proplem <//3