I teach Abstinence education and we discuss std's all the time. If you are only "almost positive" you don't have an std, then you are not sure enough. You need to get checked or tested for all std's. There is no way to be tested for genital warts which I believe can also cause PID. The only way to tell if you have genital warts is if you have a wart come up on your genitals. Sometimes these warts start out so small it can be extremely difficult to tell. One other thing. If you have even one sexual partner (and he has been with other people)through out your life- you could definately have an std.