Morning, so @amal is right in that sensation in the hand is governed by 3 nerves. The Radial, Ulnar and Median. The pinky side is pretty much all Ulnar so it is odd that you are getting sensations on the contralateral side to the implant.
That being said though, there is really no motor involvement at this point as the main movements of the hand and fingers are through forearm muscles and tendons. If you have somehow managed to damage a nerve, as the sensation is minimal and transient it will likely resolve entirely. This bruising of the nerve sheath is called Neuropraxia and the hall mark is complete recovery. If you are still getting sensations 3 month down the line then seek advice but I wouldn’t worry.
With regard to the vein, again this is not going to cause issues. Either the vein will move or a communicating vein will take up the slack. It’s very common in people with vascular issues.