Too little breast milk?? Help!

Elizabeth • 28 year old, happily married! Two miscarriages within 8 months. Praying for our Rainbow baby*
My little guy is 9 days old- I began pumping to build up supply (and since I will be going back to work soon enough).. I can usually get a good 3 oz out of left Breast but only about 2 from right during pumping sessions. Is this normal to have such varying amounts? My right breast does occasionally hurt me- so I try massaging it to help increase amount. Any other suggestions- or jus some reassurance this is "normal" so early on?? Thank you !!