I have a mouse in my bedroom?

I have a mouse in my bedroom and ive put down poison in corners and under my bed,when I put it under my bed I left it for 3 days.When I came back there was mouse poo surrounding the poison.But the next night when I slept in my own bed (I have been sleeping in another bed for 3 days) I still heard scuttling under my bed and in my room. Would it help if I let my dog run around my room so the mouse would smell its scent and get scared?And why is it stillalive if there was poo around the poison. I have cleaned changed my sheets of my bed and hoovered and mopped underneath it and around it(my bed). So what should I do? Please please answer as I am terrified of mice! Oh, and I am pretty sure it is only one mouse. And any suggestions would be helpful!!!! Thank you! :D