Well, this is about demand and supply.
Naturally, when you latch more on the right side, your right breast supply would be more as well.
Not to worry about this as this is quite common,
For some mummies that I know of, they only fed on one side but of course if you can feed on both, it would be ideal.
You should try to encourage your baby to latch on the left so as to stimulate the left breast,
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