Pumping is leaving me so lopsided!

Baby boy is almost a month old. This was pumping for 15 minutes at 10:30 am after I had fed baby. I always offer him the left breast (smaller output) first and try to let him drain it as I’ve read that helps, but so far I’ve seen no improvement. Any tips? As of now, I am pumping twice daily first thing in the morning (usually more like 7 am, but he actually napped this morning!) and before bed.