I tried to pleasure myself, no semen came out

I am a 16 years old boy.. About to get 17 in a few months. The thing dat has been worrying me for quite a while now that I hadnt even thought of masturbating until last month. I always thought that it was gross and porn never turned me on as it did to most.ppl my age. Nevertheless when I tried masturbating last week no semen came out and I am pretty sure I was doing it right.. I watched a video to make sure. I am very worried. I tried sharing dis issue wid a close friend and he told me.maybe I was sterile and.wouldnt.be able.to bear a child. I do get wet dreams in which my whole bed and trouser gets wet but very infrequently. Like after 1.5 months. Whenever I watch porn and masturbate a little.semen comes out.a few minutes after. A few drops of the thick gooey stuff. The close friend i mentioned earlier.suggested that perhaps I hadn't reached puberty which was out of the question and stupid since I have facial.hair for 3 years now and hair all over my body.. I need help people.. why am I not able to.produce semen