I think i have pectus excavatum, was nvr diagnosed cuz it didn't develop til puberty. would you recommend i get it checked out for official diagnosis?

Possibly: Well...if it seems particularly severe or is associated with shortness of breath or exercise intolerance you may wNt to be seen. On the other hand, if it is not causing you any apparent trouble , you could wait for an annual checkup with your primary care doctor and mention it to them. In a skeletally mature patient, not much can be done for it other than surgery, and has to be severe for that.