Mirena causing milk production problems?

Yaniliz
I was so proud of my progress. My baby is two months old and currently hes drinking from 3 to 4 oz each feeding. I went from 2oz a session to 7oz a session by pumping, breastfeeding and taking my supplements but since i got the Mirena on in three days my production drop to 5 oz, and at the 7th day i drop to 3.5 to 4 oz per session. I havent change my habbits and schedule but i did notice im not getting engorged breast. Also my son has mayor problems taking my breast as it used to. Im mainly pumping. I try always to make him latch buy after a min or 2 min he pushes breast away and cry.Should i be worry? Luckly i have a months worth of milk stashed on the freezer. I just dont want to dry up after all the hard work and i wish to reach the year.