Preschooler- aggressive behavior?

DS is almost 3.5. He is very social and usually a good guy. Lately he has been very aggressive though- randomly pushing a kid at the park bc he didn't want o play with him, a lot of pushing. Today he kept hitting his friend bc he said he didn't want her playing with something. I was so sad @ this bc sh was so upset n he still did it. I know he is at a difficult age but what to do? I have him apologize and I remove him for a timeout or take something away and we talk about it. Any advice? He finished school so we are off schedule and I've been sick but still I don't want this pattern to continue. So not sure if he's acting out bc of these things. Thanks for any advice.

Re: Preschooler- aggressive behavior?

DS went through something similar at that age. We were consistent with praise for good behavior and punishment for bad behavior. And very very thankfully this blip passed.

Hang in there, be strong with him and know that better days are not far off.