Breast milk?

When did your breast milk come in? I’m 28 weeks and worried that I haven’t had any leakage yet. Is this an indicator of low milk supply? I know milk doesn’t come in til like 3-4 days postpartum but I’m not a pro on any of this. I see a lot of girls due in January like I am, complaining about their boobs leaking and I just don’t have any of that