Yes, your plant has definitely started flowering.
With autoflowers, it’s not uncommon for them to trigger flowering early if they experienced any stress early on (even minor issues with pH, light, or temperature). This usually results in a smaller plant, as it prioritizes finishing its life cycle over vegetative growth.
A few quick tips:
Nutrition/pH: Since you are using coco, ensure you are strictly monitoring your pH (ideally 5.8–6.2) and providing balanced nutrients, as coco is inert. The pale leaves might suggest a slight deficiency or a lockout caused by incorrect pH.
Flowering: Focus on maintaining stable conditions now to maximize the yield from what you have.
Don't worry, even a smaller plant can produce quality buds if you keep her healthy until harvest!