11.2s in women’s 100m is better than the wind assisted HS world record for your country and better than anyone from your country achieved in the recent 2012 Olympics. The Olympic competitors and other record breakers endured large amounts of carefully planned diets/training, likely had taken performance enhancers (some types are legal), etc; all with a plan to peak and get their best times at the major competition events. They were not able to get anywhere near that level in gym class without training, so it seems unlikely that you’d get a better time than all of them in PE class without any formal training. I’m not saying you are lying, but I think there are other more likely explanations such as the PE teacher had a timing error, you had a premature start, measuring under different conditions (not really 100m), something was remembered wrong, etc.
You might want to have some formal times done with automated electronic measurement, starter blocks, etc. If the times look promising, you might join your school tack team and/or do other training with experts to get a better idea of how far you can go.
Nobody competes at NCAA level in both sprints and long distance. They require different body types, different genetic traits, different training, etc. However, most 100m sprinters also compete in other short sprint events, like 60m or 200m, possibly 400m, long jump, etc.