They look like they’ve got a ways to go. How long ago did you go to 12/12? I know you said 13 weeks but how much of that is since the light flip?
Seeing they were auto flowering I never had to switch it to a 12/12 light cycle. They have been on 19 hrs of light, 5 hours of darkness during the whole grow cycle.
There are lots of white pistils. If you can stand to wait longer your plants have several weeks to go. If you feel desperate to ease over crowding you could try some selective harvesting. Prune your plant and smoke the buds, let the rest of the plant go longer.
Oh I see it, missed it the first time. So since auto the more appropriate question would be what week did it start flowering?