Plan B, and a period for almost 2 weeks, w/ heightened sense of smell, and nausia.

I had unprotected intercourse about 3 weeks ago, he did not ejaculate into me, but I went and purchased the plan b pill as a precaution. A week later I started my period, and am now going on 2 weeks of continuous light bleeding. Sometimes normal, sometimes dark. Along with this, my sense of smell has been heightened, and I've been experiencing nausea.

Also relevant I recently started taking a generic medication called bupropion, which I have read can have nausea as a side effect, and the nausea only lasts until I eat, then fades, but occurs even before I take the medication for the day.

Before this, I had been on break from my birth control because I wasn't sexually active. After the first week of my period I started back on my Yaz, figuring it's better to be prepared. Is this what is making me bleed?
What could be making my sense of smell more intense?

5 days after intercourse, I was hospitalized for anaphilactic shock from juniper pollen, as well as a minor case of pneumonia, was put on a heavy course of doxycycline and prednisone. Is my system just in shock?