need reassurance!!

so i know that it is very unlikely that i am pregnant but i can’t stop worrying about it so basically here’s my situation;

i had sex with no contraception (he did pull out but i know that’s not an effective method) on september 4th and got my period 5 days early on september 6th (my cycle isn’t usually regular). i got my period again 3 days late on october 7th. i’m just worried that because my cycle is irregular maybe i was ovulating during that week i had sex?? since it’s irregular it’s hard to tell. i googled it and it said you can bleed during ovulation... and i know that you can still bleed every month when you’re pregnant. plus i’ve been having back pain and stuff for no known reason.

i know that it was very irresponsible for me to have unprotected sex so please don’t come at me for that. i’ve definitely learned my lesson. i’m sooo paranoid. (i’m only 16 btw.)

please say it’s impossible for me to be pregnant!!