Is it cancer?

Dear sir
I am 43 year old male and i am working out in a gym .The last few months i felt something on my pectoral over the nipple.Is right inside the muscle.When i press it ,it moves and gives a bit of pain.When i workout it doesn't give any serious pain but a slide one.
I went to my orthopedist and he said that must be from an injury .We went together to the Ultrasound machine and he and the specialist ,found out that there is a cyst 1,2x1cm
and they both said that is not anything to worry about , it might be from an injury.
He gave me a gel which contains heparin and he said it might help to dissolve it .
Well i am still worry about it.What do you think doctor?Did my doctor made a correct diagnosis or i have to worry about it?
Thanks in advance
Golds

[CCF-RN,MSN-rf]

Dear Golds:  A Cyst is a fluid filled growth that is usually benign.  They can be aspirated if they are causing discomfort.  Heparin is used to prevent blood clotting, like a hematoma or a bruise.  Hematomas can be caused by injury.  Cysts can grow for no known reason.  If you are concerned, you might see an internist to evaluate this further.

[Golds]

when i say over the nipple i mean above the nipple.(upper -outside -quarter)
Sorry for my english
Golds