Anything you do is okay, if it works in your story. This goes for grammar, plot devices, story structure, chapter length, everything.

More along the lines of the kind of answer you probably wanted: yeah, it's fine, but don't do it twice on every page, y'know? When I was a teen I used to read YA novels by a guy named Christopher Pike. Loved his stuff--pulpy teenage suspense. But he had a bad habit of starting many sentences with the word "Yet." "Yet she did not understand why he would not look at him." "Yet they went on, into the dark." "Yet I was not afraid." He seemed to do this once every five pages, and it stood out as an unusual writerly tic.