yes it is possible to get someone pregnant this way. where I work we deal with many teen agers who believed as long as there wasnt penetration (full intercourse) they couldnt get pregnant. the bottom line is that in any minute drop of ejaculation there are millions of sperm. that droplet touches any part of a womans genitals from any source (penis, fingers or object\toys) thats millions of little dudes a swimming in her bodily fluids upstream.

my suggestion is invest in some condoms. that way your hands wont be transferring little dudes from you to any part of her privates if you dont want and are not prepared to deal with children in your life.