is this all in my head or is this real can somebody plz respon asap thanks

what are the chances that i could have gotten hiv through oral sex and fingering and technicly like 3 seconds of insertion with no condom and no ejaculation ,ive only had one partner and this is the farthest that ive gone befroe with anyone..ive had a 6 week test come back negative and a 3 month test also negative...but im worried it got covered up somehow and maybe my immune system is depleted or something...i use pot quite often and im wondering if it could bring down my immune system just enough to where my immune system wouldnt respond to the hiv and wouldnt produce antibodies,can someone plz help me to clear my head? thanks