Went off of birth control after a week, Pregnancy symptom

I started birth control for a week, then changed my mind and went off. My period was longer and I had a lot of spotting from going off the birth control. I figured that was it and the side effects were done at that point., since i was only on it for literally a week. (Loestrin 24). It's been about a 5 weeks since then and I still haven't gotten my period, it's 2 weeks late.I was very worried and started search for tips on pregnancy symptoms week by week site.Also I had had unprotected sex 2 days before going off of my birth control. SMART i know but he pulled out.. what's done is done . but anyway I'm having very single pregnancy symptom possible at this point, nausea, headaches (CONSTANTLY), discharge, hot flashes, aversion to some foods and some weird cravings, etc.. HOWEVER the problem, took the pregnancy test and it came out negative. Used first response. Now is there still a chance I am (which I am not looking to be) orrr could these symptoms be caused by something else?