Shark teeth?

My 5yr old has a loose tooth which I told him not to touch and to let it fall out by itself. Of course he didn’t listen but while he was wiggling it he noticed something and when I looked, his adult tooth was right behind his baby tooth. I’ve made an appt with his dentist but when I looked it up online, it said if the tooth is loose, I should encourage him to wiggle his tooth and get it out so the adult tooth has room to come in or have dentist preform an extraction. I was wondering if any other moms have gone through this and was given the same advice.