Hi I am going out tonight for the first time, my sil is takin baby, he is 10 weeks old and bf, he will be gone from about 5 this evening until 11 in the morn, I was planning bringing pump and just using it to relief myself if I need to, is that ok? Will my supply be effected? Should I be sitting down every 3/4 hours and doing proper pumping sessions? Thanks in advance for any advice 