I been having memory issues for a while now, i keep forgetting things often, i cant concentrate or complete tasks can it be adhd?

Doubt it: If you didn't have ADHD as a kid under 10 it is very unlikely it would appear in your late 20's. To function at your best, you need good basic health, proper restorative sleep, proper nutrition and regular exercise. I would see your doc for a health screening & seek further care based on the outcome.

Consider others: Although you may have symptoms of ADHD, you are less likely to have it if you had no issues as a child. However you can have similar symptoms if you are not getting refreshing sleep, good nutrition, have depression, have too much screen time or a large number of other causes. It would be advisable to discuss your symptoms in detail with your doctor.

See PCP: I doubt it is ADHD, but I guess it is possible that you have gone undiagnosed this long