I had to stay back today on collection to speak to his teacher, she said he has a lovely nature but by about 11.15am he seems to switch and in free play time for no reason will approach other children and push them. They have spent since 4th Sept intervening and trying to keep him busy. She tells me he is a bright boy but struggles sometimes with following the rules i.e. to stop playing and sit on the carpet, sharing etc. She wants to know what is going on in his head.
I'm now sitting here blaming myself, as my ExH and I separated when he was 11 months old and I do my best as a lone parent but is this him working through anger issues due to the past? Am I not strict enough with him? I do time outs and rewards or sanctions depending on behaviour. I do not let bad behaviour slide at home or when out and about.
The only thing he does at home that I've noticed, is to sometimes wind his sister up, there is a lot of sibling rivalry or he causes trouble when bored i.e. snatches toys off his sister and other attention seeking behaviour, which I deal with swiftly.
He's never been in day care, he just did the hours at pre school, prior to Nursery, he was tricky there too at times but improved massively during that period.
The teacher said she's going to be asking the professionals for their advice on what to do next but wanted to let me know. As with only 2 of them in there, they cannot spend the whole academic year in this situation. Which I do understand of course.
I feel like a failure. He doesn't randomly hurt his sister at home for no reason 
He was a late talker and still struggles sometimes to express himself and to say it with words not tantrums. The issues begin when in a large group of children it seems
WWYD to help improve things? Am I over thinking and this is a good thing to get him support now and resolve issues, before he's doing it in Reception or Year 1.