Should i be worried about being pregnant or is this the flu or something?

now the last time ive had was in august.i was late for a week or so after but i got my cycle for about 2 days and ive been feeling nauseous for 2 months now and ive taken tests and only two of the tests came back with a weird line that was faint and it seemed to go from the area where pregnancy indicator all the way to the end of the test so i umed it was a false positive considering the other tests where negative and my cycle is for the most part unchanged and ive been having sharp pains on my left side of my hip so im concerned something is wrong i don't myself think im pregnant im hoping its the flu or something we had used a condom but im concerned some somehow got threw the guy doesn't know that's a can of worms id rather not deal with but im not sure what to think if the tests say negative