More importantly - to answer your question, I'd need to know how YOU set it up. Did you start with mature worms? How many? Are you using the drawer method? What are you feeding your worms? What's the temperature? And have you seen any "aliens" yet.
The short answer is - it takes a very very very long time. And even then, when they lay eggs, the worms are almost microscopic. So, it takes months before your meal farm will have worms large enough to feed. Further, you really need to set up several "cycles" going. Otherwise, you'll have ALL worms large enough to feed and turning into beetles, or NO worms to feed and all beetles.