I'm lost! (I don't use Instagram myself, so I'm fumbling a bit in the dark here).
If you've managed to get into your Instagram account via a web browser though, you'll see everything that's currently on the site from you. If photos you didn't want there aren't shown, then they're not there anyway, so nobody else can see them.
Perhaps, when you thought you were viewing your Instagram page, you were actually looking at the contents of your photos folder on your phone, with Instagram waiting for you to select one to upload? That would explain how you saw all of your images while using the app. If so, you never uploaded those images to Instagram in the first place, so you've been worrying over nothing!