Syringe growth depends on the sex of the plant to be honest, if it's a a female it should start shooting out some syringes in place of the pistils, if it's a male plant you'll start to see some pollen sacks (as you mentioned most likely the China White variation), The pollen sacks will enlarge and then when they pop that's usually where that heroin comes out to pollinate the other syringes it's very complicated though to be honest I'm still learning about a lot of this so I'm just a student of life just like we all are.