First, yes in the glabellar region I usually do 5 sites on injection including one in the center at the top of the nose. This knocks out the procerus muscle.
As far as the muscle spasms and headache I can say with about 100% accuracy it's not related to the Botox. The Botox toxin stays very localized once injected. Think about it, if it went through your body your heart would stop. So I more suspect there are other issues. As someone who does a lot of different workouts I am familiar with muscle spams. And typically muscles will spasm for several reasons: not enough fluid, over use and most importantly lack of minerals such as potassium, magnesium and calcium. The headaches may also be related to the same issues.
Try some supplements for several days.