Teen pregnancy

What are the chances that I'm pregant?

I've had unprotected sex about 3 weeks ago- he did not cum in me, so I was not worried. 

But now I don't have any of my normal PMS  (and I álways get it before my period and I KNOW when its coming) 

Now my period is 4days late, which is strange because its been really accurate the last few months. 

I've been having sore nipples and headaches and dizziness and I've been feeling quite nauseous. 

So I took a hpt yesterday and it came out negative. Was it too early to take the test? 

I've been feeling like my body really need nutrition and I have loads of cravings but I never seem to be satisfied; if I can put it like that. 

Also- I am so exhausted ALL the time. 

Should I wait another week to take a pregnancy test if my period does not come? Or is this just pms? 

If I may be pregant I would just want to know because I smoke and obviously I'm stopping now until I know for sure. Don't want to mess it up if I am preggers! 

 I'm 18 years old& writing matric this year. I'll take another test in a week to make sure. So obviosuly my mind is going crazy. 

Anyone else who've had a teen pregnancy? Or did you go for an anortion or did you put up your baby for adoption? 

Please share your stories!

I am pro-life and I don't think I'll be able to get an abortion, but then again I am not sure. 

I have no idea how to react. 

Any suggestions ?