Was on an antibiotic for uti. how many days after last antibiotic should i use a back up birth control method such as a condom ? im on the mini pill.

No worries: The current thinking is that except for rifampin, other commonly-used antibiotics do not alter the effectiveness of birth control pills. This is likely presuming a person is not sick with vomiting or bad diarrhea, or some other condition that decreases the absorption of a swallowed pill. One can look up: http://www.ncbi.nlm.nih.gov/pubmed/12063491