Dumb question 🥲

I was given the green light to try expressing colostrum to help with labor (Im due Monday and currently not progressing). But I don’t want to mess up my supply for when baby comes. Ive taken my BF courses and done the research and I get that it’s supply/ demand and all that jazz. So wouldn’t expressing colostrum only a couple times a day (the recommendation was 2-3x) decrease my supply for when baby is born? Or does it not work like that until after the placenta is delivered? I don’t want to hurt my supply before I’ve even started 😬😬