colostrum?

Patience

I noticed my colostrum had started to come in around week 24. I'm 29 weeks now. This is my first pregnancy and I have no idea how any of this works. I am worried it will be gone before the baby gets here. Is it like milk where if you don't use it, it drys up or if I start leaking will my body make more or is there only so much and when it's gone it's gone?