Uneven milk production

I have a question that no one may be able to answer.  My daughter was conceived by <a href="https://glowing.com/glow-fertility-program">IVF</a>. We originally had twins but twin b miscarried at 8 weeks.  Mackenzie developed perfectly but the weird thing is she would never be on the left side of me.  The entire pregnancy she was on my right side with her knees in my right ribs.  Little part of me thinks she still believed that her sibling was supposed to be next to her on the left so she didn't move over.  
Fast forward to after she was born 7 weeks ago. My left breast doesn't produce hardly anything.  I am pumping after breastfeeding so I can have a stock when I go back to work and this morning she was very sleepy and only ate on the right side and went right back to bed. So my left breast  was not used for 4 hours.  When I pumped I got 1.5 ounces out of the right side and not even an ounce out of the left which she didnt eat on.  Im wondering if it is because my body still thinks I should have twins and since it's not feeding 2 babies it doesn't need to produce on the left.  I am doing all of the tricks.  Lots of water, fenugreek, milk tea, offering lefty am often, heat, massage during feeding and pumping and I can't get it to produce more than an ounce.  
I'm not worried that she's not getting enough.  She is satisfied and gaining weight appropriately but just wondering why it's lagging behind.