I Was With A 37 Year Old Partner Who Performed

I was with a 37 year old partner who performed fellatio on me and then I ejaculated all over my tummy. We wiped it off with wipes.After 10-12 minutes I rubbed her vagina with my hands first over her pantyhose and then over her panties.My concern is what if microscopic quantities of sperm was left on my hand while wiping off my semen and then it passed from my hand to her vagina while I was rubbing her.My hand was dry or I am tempted to think so. And while both the fabrics were very light I still couldn't feel any liquid on my hand while rubbing her. What are the chances of an accidental pregnancy here. I am really freaked out