Shark teeth

So my 6 year old has not lost one tooth. None of them are wiggly or ready. I’ve always thought by now he should be getting close?! But no. Anyway, he brushed his teeth last night and asked me to help him do it better so I went in and did and I noticed he had two of his adult teeth coming in behind his baby teeth. They already broke the gums so it’s visible. I felt his baby teeth in the front and they aren’t wiggly or ready! Is this concerning? Do I give it more time or set an appt for the dentist??

My older daughter lost her teeth at age 5. So I know every kid is different but I don’t know what to expect.