Period is 35 days late!

So I started taking my BC pills in May. (Lo loestrin Fe) I am having unprotected sex with my boyfriend. I take my pills everyday and at the same time most of the time. Sometimes I may be like 30 minutes to and hour late. But I still take them everyday. But in July my period lasted almost three weeks. But I haven’t seen my period since. I have no sore boobs, no nausea. I had some cramping here and there. I was kinda fatigue about a week ago but that sub sided. I took a pregnancy test in the middle of August and it came back negative. I haven’t taken another since then. Has anyone else had this problem? What should I do?