Misconception on PRE-EJACULATION

PRE-CUM itself does not contain sperm , It is a clear fluid that is produced by the cowpers gland 
And it's purpose is to flush out the penis before ejaculation 
HOWEVER
You CAN get pregnant from left over sperm in the urethra that leaks into the pre ejaculation 
So answer is 
Pre-ejaculation cannot get you pregnant itself however you can get pregnant from the pre cum because of left over sperm in the urethra 
How to get rid of the left over Sperm 
Make sure  your  partner urinates after ejaculation or before sex. Whenever he prefers 
Now nobody ask that question again haha :)