I have been BF for 6 wks now and want to start expressing so my partner can feed DD and i can go out for the day for a break. Also worried if I don't get her used to taking a bottle that she will refuse it. I wasn't sure though how of often should I express. Do I just do it as and when I need to or is it best to do it more regularly- One bottle feed a day or one bottle feed a week so she is used to taking both ok. Also how many ounces of expressed milk should she have on a feed- is it the same as what she would have if she was having formula?