M 60mls is great! When your milk comes in you should get more. I get aches under my arms when my milk is coming in And getting more out of one boob than the other is completely normal too- my right boob was my power boob I used to get 100-130mls out of the right and 30-70 out of the left. Amounts vary on the time of day too. Your doing so well!!! Xxx