At 30 weeks, your baby weighs about 3 pounds and is approximately 15.5 inches long. Your little one is now very conscious of the environment. Not only can your baby hear your voice, but he is able to distinguish your voice from a voice belonging to someone else. Even though your baby is waking up and sleeping in cycles, just like any other person, his sleep cycle may be very different from yours. The lungs are working at near optimal levels now.
If you feel a rhythmic twitching your your belly, it's perfectly normal — it means your baby has the hiccups!