Not sure. I've always wondered why I could take 100 first response tests and get 100 negatives but take the same amount in clear blue and get "pregnant" on every one. I guess the hormone isn't being picked up in the name brand ones for some reason. Some people get negatives after getting...
Yes. You could be. You've had sex. And yes its too early to tell. And what you need to do is get your butt on some birth control. Trust me, I know first hand that being a teenage mother is not an ideal situation for anyone.