As your boy friend sucked your nipples and you sucked his penis and his semen was smudged on your nipples and not into your vagina , even your boy friend does not inserted his penis into your vagina and he only wipes his hand on your nipples pored with semen , if he puts his finger even after wiping the semen , even than pregnancy
is not possible , because pregnancy is possible only after intercourse completed and proper sperm motility
into the vagina and Fallopian tubes and by reaching the sperm into the ovaries which are to faraway from Vagina in your body.
so you don't worry about your pregnancy , which is not at all possible as you described the situation in between you and your boy friend. so you definitely forget the fear of pregnancy and take care.