You can get pregnant from pre semen. The chances are much lower than semen but it's possible. If you're 10 days late you can take a pregnancy test now and should get accurate results.
If he never entered you or finished you cannot be pregnant. Your period could be late because of diet, exercise, stress, o r hormone changes.
so should i worry about it.. my periods is almost 10 days late .
Precum does have sperm in it. I think there's a chance,a small one but still