Toddler reactions to pregnancy?

K.

My son will be 2 in just a few weeks - January 18th - and once we’ve received confirmation, I want to start explaining the pregnancy to him. Obviously he might not understand it completely, but I already feel as if he is aware - he has been hitting and jumping on my stomach more than usual (we’ve been teaching him not to). Has anyone introduced a second baby into the family with a toddler before? What type of reactions should I expect?