Is this really what you think it is? :) if it would have been an auto, by now would have been ready to harvest. It's a regular/feminized but indeed looks very small for 3 months. Looks more like 3 weeks. Are you sure it's 3 months? or maybe a typo mistake and it's 3 weeks?
If it is 3 weeks, it's right on time. A bit too tall, light might not be as powerful and/or it's hanging too high for the plant.
If you want constructive help, I'd suggest doing a diary for the plant so people who are trying to look into your problem will understand the environment, habits, intentions and plans for this plant.
Best of luck!