Can anyone please help me with this!! I am not sure if it is gynecomastia..

[thednd]

i am 5'10 and weigh about 138 pounds.

[Dr. Elliot Jacobs]

You are extremely slender so that any excess tissue on your chest could technically be called gynecomastia (which can be fat, breast tissue or commonly both).  Although your photos are poor, you do appear to have a minimal amount of excess tissue.  You could certainly deal with it by wearing a compression shirt to provide a better contour.  If not, and if it continues to bother you, then perhaps consult with a surgeon to get another opinion.

Dr Jacobs