Speech delay

Does anyone have a child that is speech delayed? My 2 1/2 year old says words but not speaking in full sentences just yet. Should I have him evaluated? He knows his colors. Know how to say his Abc. Can identify his body parts. Can follow instructions if I tell him to throw something by away in the trash. He copies off of me if he see me doing something like sweeping he will got get his broom and do it also. It’s a lot of things he can do. My only concerned is he loves the “finger family” song he repeats it several times throughout the day. And it’s like he has a weird obsession with my elbow he’s always touching it. I think he may have some sensory issues not sure. Do you all think I should have him evaluated?