When i wae up after a while i come to notice this liquid coming out of my private part it is not semen, but i dont konow when it will actually come out, what happens if it came out`

In the name of Allah, Most Gracious, Most Merciful

Assalaamu `alaykum waRahmatullahi Wabarakatuh

The liquid you are referring to could either be madhi or urine drops. 

You should check yourself before Fajr salah if your trousers or undergarment is soiled or not. If it is not soiled, and you are sure it did not come out while performing salah, then your salah is valid. If your trousers or undergarment is soiled, then you should change your trousers or undergarments or at least wash it and perform Fajr salah. Your salah will be valid.

In order to avoid doubt after making Istinja (wash after relieving), you should sprinkle water around your private part and in the undergarment. If you are not sure of any liquid coming out and are doubtful, you could attribute that to the sprinkled water. 

And Allah Ta'ala Knows Best

Wassalamu Alaykum

Mufti Ebrahim Desai
Darul Iftaa