30y/o m experiencing urine leakage (very clear, non milky) after pee and later on. i notice minor dripping and small stains in underwear. urination mostly normal; no pain or urgency, slightly less stream. all test for uti/std were negative. thoughts?

You are somewhat young to have this problem. You should see a urologist for a prostate exam. In the mean time I advise these things: do pelvic exercise (you can look up this exercise by google it), do not rush when voiding, make sure you empty your bladder well although there is always some residual, milking your urethra from bottom to top to get rid of the remained urine in the urethra post void.