You actually only asked one question!
But yes, you typically receive a port when you have undergo chemotherapy. It’s not too bad of a procedure, about a 30-45 minute surgery under full anesthesia, and you’ll probably have it in you for a year (for the full duration of Herceptin). My wife has not been bothered by it for the last six months, sometimes it may itch. Regarding the surgery, it will probably seem like cake to you after finishing your major primary surgery. Based on your presented pathology, it does sounds like you will receive chemotherapy – which is good and very effective for Her2+ breast cancers! Also, way to catch it early and opting for mastectomy -- considering your strong family history of breast cancer (it sounds like a good idea to me!).