New and unsure

hi everyone

i have joined the community as there is a strong possibility my little boy (4yrs old) has ASD. It's really early days - school have been having problems with his behaviour in the classroom. I'm feeling pretty stupid as I haven't noticed. I'm a health visitor and to me my son has just always been the way he is - never a problem.I think I've adapted how I am with him (compared to my older son) because I'm familiar with behaviour strategies but I think I've inadvertently been masking symptoms. I've had family who have said the same as school. And now when I piece all his little quirks together, it hits me in the face. The school SENCO is observing him next week. Should I be taking him to GP too or will things happen from school? I'm totally confused.