On my penis i feel a cord like thing, starting from the bottom of my shaft to like the middle of my penis then it goes to the right. i don't know if its a vein i am feeling. it looks like a blue line.i have had it for years now. is it a problem?

It is vein if that blue cord flattens when you push the cord from the tip to the base of your penis, i.e. you flush the blood out of the vein so it collapses. In contrast, the cord will engorge if you push from the base to the tip of the penis. The veins are always there on the penis but I guess you just recently noted them.

Sometimes the dorsal vein thromboses and heals by forming a cord like structure. If you have no pain and normal erections do not worry. But for precise Diagnosis you have to be examined by a Urologist