I currently holy J-1 visa. I will adjust to H-1B status next Feb.(Already approved)
So the key is, do you see an I-94 for H1 at the bottom of the approval notice? If yes, you are fine to re-enter from Canada to US using that H1 I-94. You must have an H1 I94 when your H1 starts in Feb, or you have to leave US for visa interview and then re-enter to get an H1 I-94 at POE. After next Feb, your J-1 I-94 becomes invalid.