Blac Chyna Bump in the Road with Amber

Blac Chyna seemed to be showing the fruits of her labor with Rob Kardashian, because we're seein' a baby bump.

Chyna showed up to RuPaul's DragCon Saturday at the L.A. Convention Center with BFF Amber Rose, who was a featured guest.  She was hawking her MUVA schmattas.

It was not without drama ... Amber ripped her dress getting out of her SUV on the way in.

She's tight, for sure.