When I try to erect my penis. N after sometime when I used to ejaculate I control it. But few minutes later when I go for washroom for urine. As soon as my urination overs I discover that after my urination few drops are falling which is not urine. And that thing was like a sticky. Sperm in liquid. And I have noticed many times now. What could be this reason and why this is happening. Should I concern doctor? Please help me out.