My LO is 6 weeks old and I am returning to work soon where it will be difficult to keep up on my rigid pumping schedule (I can just keep up with baby pumping every 3 hours). Our plan is to supplement formula at night (hoping for an added bonus of a little more sleep). LO usually puts away 3.5 to 4 oz per feeding of BM so I gave her 1oz formula 3oz BM at one feeding on day one with no problems. On day 2 I did 2 and 2 at one feeding and tonight we tried to do 3 to 1 but she took the formula and wouldn't take the BM because she seemed satisfied. Did I do this right...I REALLY don't want her to get constipated. Am I being to cautious? Don't formula fed babies eat more at one time than BM fed babies? Suggestions, tips and encouragement welcome.