From Discover Magazine:
The patient was a 15-year-old girl employed in a local bar. She was admitted to hospital after a knife fight involving her, a former lover and a new boyfriend. Who stabbed whom was not quite clear but all three participants in the small war were admitted with knife injuries.
The patient was well aware of the fact that she had no vagina and she had started oral experiments after disappointing attempts at conventional intercourse. Just before she was stabbed in the abdomen she had practised fellatio with her new boyfriend and was caught in the act by her former lover. The fight with knives ensued.
http://blogs.discovermagazine.com/discoblog/2010/02/01/ncbi-rofl-thats-one-miraculous-conception/A plausible explanation for this pregnancy is that spermatozoa gained access to the reproductive organs via the injured gastrointestinal tract.