Well, you see...
A girl hormone and a boy hormone go on a date after making eyes at each other at the local gym for a few days. The boy hormone tells funny jokes and gets the girl hormone a little tipsy on cheap mixed drinks. They go back to the boy hormone's condo for a few more drinks and to "relax".
Several months later, the girl hormone realizes that her tummy looks funny and her Aunt Flo hasn't visited for some time. In a panic, she calls the boy hormone - but his phone is disconnected and she was too drunk that fateful night to remember where he lives. She decides that everything will be okay and moves on without him.
Several months later, the girl hormone busts a litter of baby vials out of her magic box, and decides to put them up for adoption. Little baby vials of hormones are adopted through UGL adoption agencies - ensuring good homes for these little tykes every day.
Now you know the seedy truth.