I was fasting. And in the day time I saw that little drop of sperms coming out of my penis will it break my fast. I did not touch my penis I was alone in my room and I was trying to sleep I dont know why this happend.
This would not break your fast since it was on accident. a better explanation is found on islamqa: Praise be to Allaah.
There is no sin on him and his fast is still valid, because Allaah says at the end of Soorat al-Baqarah (interpretation of the meaning):
“Our Lord! Punish us not if we forget or fall into error”
and it was narrated in a saheeh hadeeth from the Messenger of Allaah (peace and blessings of Allaah be upon him) that Allaah said, “Your prayer is accepted.” And it was narrated from Abu Hurayrah (may Allaah be pleased with him) that the Prophet (peace and blessings of Allaah be upon him) said: “Whoever forgets when he is fasting and eats or drinks, let him complete his fast, for it is Allaah Who has fed him and given him to drink.”
The same applies if he has intercourse, forgetting that he is fasting. His fast is still valid according to the more sound of the two scholarly opinions, because of the verse quoted above and because of this hadeeth, and because the Prophet (peace and blessings of Allaah be upon him) said: “Whoever breaks his fast in Ramadaan by mistake does not have to make it up or offer any expiation.”