Don't worry, it is perfectly normal, like the other mom said, it is reaction to mom's hormones, or it is what the older generation called 胎毒. It will go away in a short while or a few weeks.
Don't worry so much, it will affect the milk production if you worry.
I ate EVERYTHING during breastfeed, Doctor and nurse both said no need to戒口 except things that contains LOTs of caffine.