I had unprotected sex today on my ovulation day is it possible to get pregnant from pre-cum?

Yes possible!: Unprotected sex at ovulation (highest fertile time) = highest possible risk for pregnancy. Nobody knows the exact "science" of pre-cum, but unprotected sex means unprotected. If you don't want to be pregnant stop having unprotected sex; if you don't mind the risk you can go ahead. Don't fool yourself NO time is completely free of risk. Good wishes, hope this helps.

Possibly yes: Most studies have shown low levels of sperm or no sperm in pre-ejaculate with sperm not being motile (however, don't know how promptly samples were examined). One small study published in 2011 showed that there are some individuals with a high motile sperm count in pre-ejaculate. See: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3564677/