How can someone get pregnant on lo loestrin fe?

Usually that: Should not happen, but if you miss a pill , or did not absorb the pill properly, which could happen if you were taking an antibiotic for an infection or if you vomited a pill, u could break thru ovulate and get pregnant, no birth control is 100% that is a very good pill and the #1 pill i prescribe esp for my pts in late 30s and 40s as it has the least hormones which is safer.