Had 2 periods and 8 negative tests since my last sexual encounter 9 weeks ago; no noticeable symptoms. can i still be pregnant or am i being paranoid?

Not pregnant!: A diagnosis of paranoia is also not likely, but that's less certain. Please try not to use the word casually, it's a serious disorder! You wouldn't throw the term diabetic or arthritic around based on a single behavioral sign, would you? Also, if your belief is persistent and resists facts - it would be a delusion. Make sure to use good protection for all sex activity since you really care!