I don’t think it is a must, but more of advisable to wear to give support to your abdomen muscles? I am also 3 weeks in but my stomach area isn’t sore. I wore the binder since the day i was discharged and only remove it when i bathe. It has helped me to move around easily tho and my tummy has shrunk alot. Perhaps dont skip on your painkillers and move slowly? Also, if you wanna wear then perhaps dont wrap it too tightly, just enough to give support :) jiayou!