Can you get pregnant if your boyfriend ejaculated and sperm fell on your stomach and there was no intercourse?

Sperm ejaculated on your abdomen/stomach will not result in pregnancy - if sperm is ejaculated on the woman's outer vaginal tissue it may be possible, but not likely. The sperm don't live long outside of the body (male or female) and would have to find the entrance to the vagina, then swim the entire reproductive tract.

Sperm ejaculated in the vagina are already sent in the right direction at the cervix.

Semen on the outer tissue could cause a STD if there is any small cut or abrasion. Practice Safe Sex!