Hi
@ramber3446! There are two obvious signs of preflowering. The 1st one is the stretch, your plant will double or triple in heights while she's entering the pre-flowering stage, for a few days (up to 3 weeks with some sativa strains). Meanwhile, you will notice the first pistils appearing around the nodes, this is the second sign. Once you will notice pistils, you should slowly decrease her Nitrogen intakes and slowly add some Phosphorous+Potassium in your feedings. Hope this will help, let me know in the comments section if you need any further information. Happy growing! 👊