Do you think is early flowering?

No, I can't see anything that would indicate any primordia or as you call it, "pre-flowering". The first primordia usually occur some way down the main stem where there is a leaf/branch/main stem junction, and not at the growing top. Have a look at my diary "Holy Mackerel .. WTF?" to see some pictures of both male and female "pre flowers" or primordia as they are know scientifically. Hope this helps,.... Organoman.

Just looks like new growth but its VERY hard to tell by the pictures. When you see your first white hair, you are officially in preflower!

Looks on track to me. Some autos start to show sex pretty early I find.