Sigh :(

LO understand so many words but seems to be having a speech delay. Honestly he has flash cards, if I tell him to show me the card "Apple" he'll find it and give it to me. All he does is babble and still a lot of the time says adadada for everything. Whenever he hears an airplane, he puts his arm in the sky and babbles adada. When he sees our cat he says adada. It just kinda breaks my heart to know that he was saying words at 11 months and that all disappeared. I know it's too early to raise concern but are anyone else's tots like this?