My Ds 5/6 months has started wanting to stand quite a lot and isn’t as happy sitting on you. He is making very excitable arms and pursuing his mouth and making oo sounds, like he is very excited or overwhelmed. He is very smiley and giggly. He makes eye contact, follows sounds, responds to name. I just can’t help but worry, has anyone else’s baby been through this excited arm stage etc? Worries it might be stimming