I am a virgin but a guy fingered me and ejaculated near/on? My vagina. Probably had semen on his hands. What are the chance of pregnancy? Take Plan B?

Low risk. If semen is deposited in the vagina then pregnancy can occur. The most efficient way to get pregnant is through penile vaginal intercourse in which semen is directed deposited in the vagina. There are 4 million sperm in preejaculatory fluid (precum). It only takes one to get pregnant. Use condoms. Be smart and avoid these scares. Consider starting birth control to avoid an unplanned pregnancy.