Milk??

I’m 24 weeks and the past couple of days I’ve been waking up with a dried stain on the inside of my bra. It’s like the size of a penny and it’s just the left side...is this pre milk stuff coming in? 😂 I know it starts with a C but can’t remember the name of it. That’s the only thing i can think of so sorry if this is a dumb question. 😂🤦🏻‍♀️