Yep, just diagnosed a week ago at age 38. If you did well enough in school, and have the inattentive-type ADHD, it's really easy for it to get missed in childhood.
If you were smart enough to coast through school despite your procrastination and attention issues, definitely go see a psych for an evaluation.
The Wender-Utah scale for adult ADD is available online, and could give you a firmer indication, though obviously this is something you would want a medical professional to confirm and help you treat.