According to the APA, this starts the third trimester.
The baby is now 2 pounds and 10 inches long. And he's about 14-15 inches tall from head to toe (1 inch taller than a Barbie doll). He's almost fully developed now and the immune system is developing. The baby has a normal sleeping and wake cycle
The warning is to be careful about flying. They say to call and check with the airline when you can't fly anymore and when you need a doctor's note. The general suggestion is that after 32 weeks you'll need to check to travel.