retainer

I got a retainer Tuesday it's like Invisalign but different company so it's a little different. It's clear care. Has anyone had this or similar. And when does your lisp go away. I will have a bad lisp I think and it's obviously embarrassing and I work that I talk to people all day. I've been wearing it and talking to people anyways but they look at me like I'm stupid and my coworkers make fun of me. They said it should go away in a few days and it's only been a few but I think I still have it bad enough I don't know when it's going to go away.