Phizer vaccine and milk supply?

I got the Phizer covid vaccine the day I was discharged from the hospital from my c section. I had no side effects from the first shot. My milk came in quickly and I have had a good supply. I am 1 month post partum now and just got the second shot. My milk supply seems to be down. I pump and feed and all of my pumps have been lower volume the past few days. My son also seems to be hungrier but different than a cluster feed. He feeds and then cries like he did not eat. Has anyone experienced something similar? When will my supply go back up?