I read three chapters of 1Q48... Ushikawa tried his best to search for information of Aomame and find the connection between her and Tengo. He went to the elementary school and asked staff members there. He obtained some facts about Aomame.However , Aomame was so good at hiding that he could barely get anything really important.
At the same time Tengo went to nurse Atachi's home. He was invited to have a taste at marijuana. While he was wasted in it , he stepped into the world where he saw Aomame standing in the classroom of his elementary school. That hallucination had a great impact on him.
I read two chapters of 1Q48. Somehow there being a supernatural power , Aomame got pregnant without having had intercourse with a man.She had used the pregnancy-test tissue ,only to confirm the reality.There might be something ominous about to take place.My assumption is that I learned that while Tengo joined the body of Fuka-Eri, who hadn't started her menstruation by that time , the moment his semen surged into the womb of Fuka-Eri ,Fuka-Eri's womb opened up a passageway to teleport the semen to Aomame's uterus.That might account for this supernatural power.