Has my milk come in?

I got nipple shields today because of the pain, cracking and bleeding. Best things ever! My LO seems to have adjusted to them just fine. When I took the first one off after a feeding, it had this liquid on it. Is this my milk? I'm 6 days PP, FTM. I haven't felt my boobs get hard or engorged like I've seen others describe when their milk came in. When I hand squeeze I can see a creamy color liquid.