Clear retainer isn't fitting right?

I got my braces of yesterday and I got my clear retainer today. The top fits perfectly and I can hardly even notice it, but the bottom is funky. It kind of hurts my gums at the bottom when i put it on, I guess they're inflamed (How do I get rid of that?) but more importantly it dosn't really fit. On one side it's perfect but my molars on the other side, it's not hugging my teeth it's kind of popping up and it hurts. then when I relax my mouth my molars on that come together and I can't close my mouth all the way. Should I wait or go get it fitted again so it's snug?