Blac Chyna has broken ranks in the burger department, making a Burger King run hours after TMZ broke the story ... she is pregnant with Rob Kardashian's kid.
Chyna was in downtown L.A. with a friend, scoring a few bags at the drive-thru.
Rob -- a big In-N-Out fan -- and Chyna hooked up 4 months ago, and pretty clearly hooked up again soon thereafter.
