The Are We There Yet? actress recently confirmed that she and San Antonio Spurs forward Ime Udoka are expecting a baby together this fall.
Long revealed to reporters at Sunday's BET Awards that she was first told of the pregnancy while receiving a routine medical check-up.
She said: "I was supposed to go to Ghana to do a film and that's when I found out I was pregnant. I had a doctor's appointment to get the yellow fever shot and they were like, 'Miss Long, we can't give you a shot'… I almost fainted. It was the best moment and the sweetest surprise ever."
The star went on to claim that she is "feeling great", but admitted to Us Weekly that she has experienced some odd pregnancy cravings, saying: "I'm craving salt like crazy. I'm usually more of a chocolate girl, but I haven't been craving sweets."
Long is also mother to a 10-year-old son with former boyfriend Massai Z Dorsey.
She recently voiced rebellious teenager Roberta Tubbs on Seth MacFarlane's animated series The Cleveland Show.