Mix Feeding.

my son is 17 days old, I produce about 170ml MAX from my left breast and about 100ml on my right. I like to keep atleast 2 bottles in the fridge for him, I’m worried I’m not producing enough as he takes anywhere from 100ml - 150mls. what are the pros and cons of mixed feeding? I obviously know breastmilk has some better qualities but I also need to keep up with his demands. I’m thinking of using my EBM during the day and then Formula at night time. I feel awful as it is so please no nasty comments... I just want to know the pros & cons of mixed feeding.