Glowing Womb room bluggsac?

[Coopster1030]

In the secret room of Forgotten Crossroads with the Glowing Womb charm, in the fighting area there's a constant heartbeat noise like when a bluggsac is around, but there appears to be nowhere else to go in this room. Found no mention of this elsewhere, so just making sure that I'm not overlooking some other secret area?

[Tat011]

That's because behind you is the bottom of the temple of the black egg.