That didn't take long -- Rob Kardashian and Blac Chyna's kid is already in the family biz ... making his/her social media debut.
Chyna posted her sonogram with a long message about her little nugget, fairy tales, bundles of joy and blah, blah -- she's really happy about what's cooking in the oven.
Remember this pic. In a couple years this blob is going to be in a stroller pushed by big cousin North as they shoot a reality TV show. Look closely, you can see a tiny contract from Kris Jenner.