I had sex 1 day before i ovulated. used a condom, theres a chance precum was present, and i took plan b 6 hrs later. what are my chances of pregnancy?

Pregnancy: We can't figure your chances, we are not tellers of the future unfortunately. You have had intercourse at the correct time. You did the correct things to prevent pregnancy with a condom and plan B, so your chances are unlikely. You now need to wait and see if you miss a period and then do a pregnancy test. The best time is first morning urine about 5-7 after you have missed. Best of luck.

Probably low: Soon, you'll either have a period or be able to do a test and know for sure. Probabilities are not very useful after the behavior was done - if it could have been known before sex and precum and caused different choices, it could matter, but that can drive you nuts too. Wait and see. Good luck - you're likely not.