When does sleeplessness typically hit you after Dexa?

I’ve been having 20mg Dexa each on Thursdays and Fridays as part of my induction therapy. I’ve noticed I have trouble sleeping on days I have Dexa. Just wanted to know if this is normal or is it in my head? Usually sleeping isn’t an issue but I’m worried it’s all in my head and that redditing till midnight is making it easier to turn my thoughts into reality LOL.