Our journey through space begins when our egg is inside a follicle-like spaceship and is released from the ovary to 'free float' to the fallopian tube which is not directly connected to the ovary.
The fallopian tube does get chemical signals to go closer to the ovary but there is that free-floating mysterious journey before the fallopian journey and fertlization begins. Perhaps there is that gap so sperm can not reach immature eggs at the ovary.