Do you think I have asthma? Is it something else?

I've been coughing every few minutes for the pas few days now but i dont have any cold symptoms and i really don't feel like I'm sick. My throat isn't itchy either. Sometimes when I cough it's bcuz either i feel like I have to or if i feel that's there's a little liquid or something that just dropped in my throat then it's gone when i cough then it comes back a few mintues later. I don't think my chest has tightned, i really don't know what that feels like so i don't know if it has happened, im only a kid. A few weeks ago it happened twice where i just kept cought for like 20 minutes in my room and it was kinda hardto breathe because i felt like the air in my room was dirty or something and i keep tried to take in normal air and i WAS breathing normally but the air kept coming off as, idk dirty or dry or something. But that only happened twice and that was weeks ago, but idk if that's connected but who knows? Anyone what do you think it is? My mom's bein coughing too, i don't know whether or not she has cold symptoms but i dont think she does so maybe's it's a disease and not asthma. Thank you for answering my question. Oh and also sometimes phlegm does come up but it's an extremely small amount like tiny drops in my spit. Maybe i have Postnasal drip i think that could be very possible too. Wow it's really cool how im like 12 and self-diagnosing myself. Okay so what do u think it is?