Will my teeth move after i've lost my retainer? HELP!!?

today i lost my retainer at the beach. as soon as i got home i called the orthodontist. I need to go there friday so they can make a new mold and i will get my retainer 1 to 2 weeks later. will my teeth move a lot in those week(s) and is there anything i can do to prevent my teeth from moving? i've had my retainer since 2th of february.