Thank you for the advice I just think Im worrying myself a bit to much since the last questionable encounter I had was over two and half years ago and i have been tested three times within in a year of that encounter and i got tested for everything under sun from HIV to herpe's. And i have never had any symptoms or signs of a STD. And thank you again for easing my worried mind.
Hi and welcome. being male, i would think its possible to bruise the penis from what you describe. Normally with STD's there is a white/yellow discharge and burning when urinating or even an itching in the urethrea. If your worried maybe best to have a doc check to make sure all is in working order.