Pregnant with a toddler

So.. question for you second time (or third or fourth for that matter) moms. I am the mother of a very awesome, and very high energy, one and a half year old. I just found out I am 6 weeks pregnant with baby number 2. I am very excited about!! I have a concern I’d like some input on however. My son loves to play, and jump, and lay on me at nap and bed time before I place him in his own room. How to I keep him from accidentally hurting my new little bean? Any feedback would be great.