Three weeks isn't very long. I'd wait a little longer. Maybe closer to the eight week mark? That sounds like eternity, but it seems to be about standard.
Hang in there! There should be many others you can query in the meantime
Try agentquery (dot) com and enter your genre.
Hang in there! There should be many others you can query in the meantime
Try agentquery (dot) com and enter your genre.