Early Menstruation after High Fever?

Hi, I hope you can help me, as I'm confused and somewhat scared. First of all, my last period started on the 2nd of March, and ended on the 6th of March. A week ago (March 16) I came down with a relatively high fever. (I was stuck in bed the whole day and was throwing up. I barely ate/drank anything over a course of two days.) This was a day after I last had sex with my boyfriend. We always use condoms, but there was some unprotected penetration during our last time together. My fever went away about three days afterwards, then on the next day (4 days after having sex with my boyfriend) I started having brown discharge. It looked like old blood and had no odor. Then it became fresh blood, and until now I'm still bleeding. I don't know if this is actually my period or if I'm pregnant and this is implantation bleeding. I don't have any cramps, nausea or sore breasts. My period has always been irregular, but late (usually by a week), never early.

Now that I've explained as much as I could, is an early period normal after getting sick? Or am I possibly pregnant? I haven't taken a pregnancy test yet. I hope you can help me.