I don't understand how you are not sure when if you had sex in a bus or not. Either you did or did not. Where you impaired by alcohol or drugs.
Hello,
During erection, The penis grows enlarged and firm, the skin of the scrotum is pulled tighter, and the testes are pulled up against the body. As sexual arousal and stimulation continues, it is likely that the glans or head of the erect penis will swell wider,the foreskin retracts and, as the genitals become further engorged with blood, their color deepens and the testicles can grow up to 50% larger.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.