Breastfeed/Formula

Is it feasible to use formula/bottles for a few feedings a week? I exclusively breastfeed and haven’t gotten into pumping, so am always with my baby. I am looking to volunteer at my school a few hours a week (I miss work 🙈) and was thinking of doing formula/bottles during that time. Would baby take to formula/bottle if she’s only having it 1-2 times a week? Side note: I have a pump and a hakka but haven’t used either yet.