Quick question about BABY FORMULA?

well, my baby is 4 weeks old.. and my milk began to dry up, cause i wasnt eating and dirnking enough, so i had to give my baby formula to subsitute until i got my milk back up... my mother had some at her house from my nephew, when he was a newborn,.. it was only a little bit, i didnt need much, i ust wanted to use it until i bought my own.. so i gave my bub some of this formula... n only afterwards did i check the date... it was out of date in february this year!!!! ( she could have told me) will this make my baby sick?????