11:28 AM PT -- Ashanti apparently is pregnant after all -- at least according to Us Weekly, which is citing a source that says, "Nelly and Ashanti are welcoming their first baby together."

If true, it'd be Ashanti's first child ever ... and it would be Nelly's 3rd -- he already has two other kids from a previous relationship, and both of them are adults.

We've reached out to Ashanti's camp for comment ... so far, no word back.

Nelly and Ashanti's latest barrage of PDA has led to pregnancy speculation -- and it's all because they created it!!!

Over the weekend, Nelly, Ashanti and many more got suited and booted for the "Country Grammar" rapper's 11th Black and White Ball at the Four Seasons Hotel ... which brought the event back to St. Louis after a seven-year hiatus.

The superstar couple appeared to share an inside joke on stage when Ashanti placed her hands on her stomach, to which Nelly did the same ... making them both burst out laughing.