Greenish-yellow Discharge From My Penis. Do I Have A Sexual Disease?

Its been three days since I have had sex with my  wife and now I have a yellowish discharge from my penis, some red dots around the head and burning feeling while peeing ,  What could that be??

I know this condition from personal experience as a doctor/biological analyst.
You may have what is known as autonomos hulk syndrome(I know, crazy name ,right?). Anyway, It is commonly caused by exposure to small amounts of gamma radiation(hence the hulk link). The best method of detection is to boil water in a kettle, add salt. Stir this solution. Then, add some of the discharge to the solution. Leave to settle for a day. The next day note the colour of the mixture, if it is yellow it is an infection and will pass. However if it is greener than before, Ring David Banner, before you morph into the hulk and go on a crazy rampage. Kidding about Dave Banner, hes a bad doctor, consult your parents instead, as you may require circumcision

If you did not have sexual intercourse I wouldn't imagine its a sexually transmitted disease how ever if I was you (and a man) of course I would definitely go to my doctor as it is not normal and it is always better to be safe than sorry. It could be something simple like thrush.

If I have hpv dose a discharge come out of my penis?

To above this is probably an STI.. A Burning pain indicates Clamidia!