Am I being petty?

So my son is breastfed and a formula baby just simply because I can't produce the quantity he eats but I still can pump about 4 ozs every two hours. He only eats about 3 ozs every feeding now so my milk usually lasts awhile. Well today after pumping I only produced 3 ozs I noticed my husband came out with a full to the brim bottle and was shaking it. I asked where's my milk? He said this is your milk, I just added the left over formula to it.... I asked him not to do that next time and now he's mad because that's "wasteful". Maybe I'm just butthurt about not being able to fully have my son as a breastfed baby, but if I'm going to pump a bottle I would like him to drink that before the formula and I currently don't like the idea of him combining the two. Am I being petty?