Just noticed space in teeth.?

I got my braces off like a year ago. i had them on because i was missing two of my teeth. and it closed the spaces. Well i just brushed my teeth and noticed a small space between my two front teeth. i wear my retainer 24/7 (because i have two fake teeth) I don't want to go back to the orthodontist. the space is like the thinness of plastic in a recyclable water bottle. is it anything to worry about?