What are the chances of gettin pregnant off pre cum on ovulation day?

Indeterminate: Nobody knows exactly, but it's not zero if you are fertile. If you are actually age 47, the likelihood is miniscule, though.

Don't know %: 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/