Pregnant with a toddler

Brittany👨‍👩‍👦‍👦☕️ • 28 yr old Boymom of two wonderful boys, Blaine and August. Currently pregnant with #3! Due December 2016 😍
My son is 3.5 yrs old and he is sooooo busy! Constintly jumping and climbing on me. He knows I have a baby in my tummy but some times he forgets. Or when he gets mad he kicks and I'm worried he'll kick my stomach. What do you guys do in this situation or how would you handle it??