Both breastfeed and formula

I notice i feel sometime pain my nipples due to tension and sore after nursing. I don’t know if it’s normal to have less nursing for 1-2 times but more pump to give breast milk that i have hard time to produce more milk supply. I do alternative both breastfeed and formula bottlefeed because depend on how much my milk is not enough then use formula.

Hope not I’m the only one who have both breastfeed/bottle-feed.

Do you think it is ok to have both them safe for baby?