Outcome of post lumpectomy results: total axillary clearance of right arm, surgery next Monday.

The drains are a bit creepy and uncomfortable but they probably won't keep you awake at night. It is impossible to guess how long they will be in; some people stop leaking in a couple of days some, like myself, can ooze for the empire and go on for weeks. 
It's nice you will have a nurse call in to change the bags--in some areas you have to do them yourself which, while not difficult, means you don't get that daily support, reassurance and advice.
Good luck @viking1