At&t hotspot question

so, i'm in the middle of changing ISP's, so no wifi for a few days for me, and i wanna use my iPhone 6 as a hotspot till i get wifi. thing is, i'm not totally sure if there will be additional charges. reason being is being i have the 25gb no overage charge family plan, so even if i go over my 25gb while using my hotspot (will be on my laptop) will the speeds just be reduced like it would be on my phone? or would i get charged for it?

would appreciate some enlightening. 😅
thank you.