One every few weeks More if you fantasize often, less if you don't. Other factors can cause wet dreams too.
Everyone is different. Some have frequent WD, others have none. Both are normal. Your body will do what is right for your body. If you allow your body the time it needs to heal, it will heal, so no "testing the plumbing" - it will work fine so there is no need to check ! One day at a time is how we all succeed.