I had sex w/o any protection last Wednesday. And I'm not on birth control. This week I am light headed sometimes. I get headaches almost everyday. I'm always hungry. I eat like I'm eating for three but after a few minutes I'm not full at all. I'm nauseous all the time! I'm just not myself. What's wrong with me?

Yes, you could be pregnant. Any time you have sex you can become pregnant but especially with doing it with no protection at all.

However, only 1 week later is too early to tell for sure.

Do you know how pregnancy works? A week later you wouldn't be having pregnancy symptoms. So the symptoms you're having are most likely not due to pregnancy. That's not saying that you aren't pregnant. There's a good chance, since you did have unprotected sex. But the symptoms you're having, unlikely that they're due to pregnancy.

Wait at least 2 weeks after your period is due (if you miss it) and then test using first morning urine.

I'm sorry. I meant to include that I've been sexually active w/ my partner since October maybe. We've never used protection. He'd pull out before he came. But his pre- was definitely inside me. Does that make a difference?

Nope, you could still be pregnant.

Pulling out does not stop pregnancy, just lowers amount of sperm, plenty of sperm in the early fluids often.

Just that it would not show up after one week.

This is also signs of a worry or nervous issue itself, is there other problems going on ?