Can i get my girlfriend pregnant from pre-cum if i masturbated and ejaculated 6-7 hours before having (not sex) but naked grinding on each others private parts ..?

The basics: There must be a transfer of sperm containing fluid from the male to the inside of the female genitalia for pregnancy to occur. No sperm transfer=no pregnancy. If you can come up with a setting where ANY PENILE FLUIDS transfer to the girlfriend, pregnancy would be possible.

Pregnancy is not a risk from what you described. However, your behavior could result in pregnancy if intercourse occurs and you are also exposing yourself to STDs. Visit this site for safe sex guidelines: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines Get HPV vaccine. Wish you good health!