Ive taken an advil (ibuprofen) pm 2 tablets, how long before its out my system to breast feed? should i express the milk first then feed?

Yes. : Depending on when you took the medication breast feeding is possible. If u took it just before breast feeding then the medication will take some time before getting into breast milk. Next time try to take medications after breast feeding. Also a good website to find out more is : http://toxnet.nlm.nih.gov/cgi-bin/sis/htmlgen?LACT. U can check any medication and be forewarned.