Chance of being pregnant?!

Ashley
So i am 18 and not ready for a kid. I know the only way to know for sure is to take a test. But are some symptoms of pregancy 
Major headaches that last days
Dizziness 
Lightheaded
Fainting 
Stomach pains every so often
One night hving pain in boobs that felt like they were on fire
And now noticing that my nipples are darker and seem to have gotten or formed a layer of ski or crusty something over them. 
Please give opinions and no hurtful comments im scared