Blac Chyna -- My Birthday Party's Betweeen a Rock and a Hard Place (VIDEO + PHOTO)

Blac Chyna threw an epic bash Tuesday night in Hollywood, with Rob in tow ... and she hawked her wares like a seasoned Kardashian.

Chyna threw the party to celebrate her birthday -- which is today -- and sell her new Chymoji.

We got inside the Hard Rock for the shindig, and clear evidence she's got a baby inside her ... there's agua at the table.

She's jumping on a plane Wednesday for Miami, where she'll host a strip club event.

And check this out ... Rob surprised her with a flower or 2.