15 Male: Why do i drip after urinating?

I have no problems urinating. Its after that when i finish around 10 seconds to a minute later, if i try to bend down and pick something up or get on my hands and knees and try reach for something under the sofa, i drip 1 drop. It frustrates me and kind of worries me. Could u you think of any 1) Reasons for this happening and solutions for this. I have had this problem for about 3 days. Thanks in advance.