The short answer is NO....at least not all.
There are several waves that spawn. The first wave always comes in when that water temp starts to hit the 60s and so on. and then more show up with each extended warm period. Cold nights like we have had will back them off!
One of the best ways to know for sure is having a good network. If guys that are die hard trollers are catching big females in 10-25ft of water still fat and full of eggs, then they havent quite made it in yet.
The last few trips, ive caught many males on the banks that havent showed much of their "tuxedo" (I know this after filleting them out). This tells me that they are fresh on the bank now, and looking for a place to make their beds. The females will follow days later.
Traditionally, Lake Norman is about a week or 2 behind the other lakes.
This year they are a bit behind schedule, oddly because we have actually had a "spring" for once!! I think next week will be the time to be on the water!