I think my once excited child is becoming worry

My first child who is four years old recently started showing jealousy behavior. Like my child who was once very independent is becoming dependent. Behaving like a toddler all over again. Crying spells over simple things. Lately she’s been attempting to hit my stomach (31weeks prego) in a playful manner. At first, I thought maybe she was doing it on accident. Until today, when she actually did it intentionally. Can I get some good advice? Please?