I'd just go for a quick physical... Blood pressure, complete blood workup, etc. That should rule out anything serious, and then you can decide whether to say about ED or not. Tell them you came in because you work out, and you want to be sure everything's safe. Maybe say you feel OK, but you haven't seen a doctor lately. That will cause them to look at all the same issues that might cause ED. Also it will tell them you respect your body, and you probably aren't there for free pills, and you probably don't abuse your body. You don't have to say that when making the appointment, or even when the Doc asks why you came in. In fact, if you say ED, they'll just think you want Viagra and maybe you don't even have a problem. You can mention it later, but I'd say not right away. If they say high blood pressure, THEN you can say about ED. Reason is, that blood pressure pills are known to cause ED problems, and they can try different kinds that don't cause that as much or at all.
Charles