I am a low yield bm mother who is supplementing my baby with fm once/twice per day. I am trying to let baby latch as much as possible and pump 4 hourly. My baby sucks almost 1-2 hourly with no standard timing/ schedule. Sometimes even shorter interval. Problem arises when baby cries when it's about my time to pump, making me to miss my pumping session. Anybody has the same problem with me? And how do you cope with it?

Why do you think you have low supply? Pump output is not an accurate way of gauging your real supply. If you can latch your baby, there's no actual need to supplement with infant formula. Feeding on demand is the correct way at 7wo. If you wish to increase supply, try pumping after you are done latching your bub. You may not get much, but it's a way to stimulate your breasts for more output. Gradually, your pump output after latching will increase. Try to pump for at least a letdown, that would suffice. There's no need to watch the clock when you pump.