I Feel Like I'm Dying--is It Pregnancy?

To preface the timeline of events that have occurred: my honey and I had unprotected sex on the last day of my period, which was on the 7th of this month. My next period is scheduled to begin roughly on the 30th.

Beginning saturday (about 10 days after intercourse) I came down with what started to feel like the flu. I spent all day saturday trying to find a food that didnt repulse me, and sunday was spent in bed.

Water turns my stomach, the smell of ciggarettes (my favorite vice) and beer suddenly disgust me, and I will be overcome with a wave of naseua at the most random of times (like in the middle of my quarterly financial report at work...)

on monday, even though I was dizzy and naseaus, I frantically cleaned my house because the thought of germs was making me sick.

Now, this morning, my back is killing me. I have never experienced this kind of incredible pain in my lower back. Combine that with headaches and I am just about ready to die. On top of all of these symptoms, I think I have a yeast infection, and I can't kick it because I can't hold any fluids down. Help me. I theoretically can't take a test untill next week, but I would love to hear your input. Do you think i'm pregnant?

And the fatigue! Sunday I slept for about 20 hours, only getting up to choke water down or pee. And i've gone through about three boxes of kleenex at my office due to a runny nose, but no matter what otc meds I take (sudaphed, alavert...) my chest is killing me and my nose is nonstop running.

I have incredible heartburn-like symptoms...And just this morning I started to get unusual cramps. Typical cramps occur in my abdominal area, but these cramps are super low and unbearbly painful. The cramps, which bend me over, occur more towards the back (towards my butt) and are very low. I'm getting scared. Also, I had my period twice this month. The first period ended on the 30th and I started again on the 3rd. Why is that? (i dont have insurance yet through work, otherwise I would consult a doctor regarding all these issues...)