Will i be okay if i took 3 non-asprins at the same time?

Depends on : Which drug (name, but probably acetaminophen?) and dosage (probably 325 or 500mg) and your body mass. Take the worst case scenario: you took 3 tabs of 500mg which is 1500mg, and you weigh 80 lbs. Your toxic dose is probably about 2400 mg in 24 hours, so you should be ok as long as you don't take any more. If any of these assumptions are wrong, then resubmit your question with corrections.

Not a good idea : Not a good idea on any regular basis and especially at your age. Why do you need medication? If you need it for sure , take only the amount needed and not more. To much Aspirin can cause bleeding and stomach problems among other things.