The one you're getting from the right breast is more than the left one, or vice versa.
I am pretty sure some of the breastfeeding mommies out there do experience the same thing. I just dont have the time to look up from the net on the reason behind this. Whether it's purely hormonal thingy, or due to lack of stimulation from one side, or problems in latching, or anything.
During Firas's time, i got more EBM on the right hand side, while now with Ammar i got more from the left breast. I rotate equally between both left and right side during direct breastfeeding, hence i strongly believe my case is not due to lack of stimulation. In fact i've tried to give continuous direct feeding on my right breast for few days to see the 'after-effect' of this action but as you can see below, the result is still the same.
right breast 3oz, left breast nearly 6oz.Whatever the reason is, it's 'fitrah' determined by Allah and insya Allah is enough for your baby...