I am going to be in a wedding in one and a half weeks and don't have any spare bottles. I don't think I can pump enough for the whole day before it arrives. Would it be harmful to give my LO formula for just that day? I imagine it might be good to give her a couple bottles of it just to introduce it so that Grandma doesn't have a baby freaking out on her. I'm not concerned about my milk supply because this would just be temporary. Any advice, thanks!