I look for the buds in veg to start showing their girly parts well with the ones from seed.
Size-wise it's roughly around your larger ones (I do not use calendars, just stage of growth so I have no idea of "weeks" or "days") but even the smaller ones will get large with flower flipping them now.
You could flip now or even get a screen and tuck for a while. That does extend growing time.
If you just want it to finish so you can fill a case of canning jars up; flip it. A bud in a bowl is better than waiting 3 weeks more just so you have 1.25 bowls instead.
I've flipped one with less than a dozen fan leaves and barely a top on it, but I got a 1/2 gallon jar from it.
It almost looks like something splattered on it but ???
The rest looks great, I would not worry unless it happens again.
If it is a "splatter"maybe it was the nutes in it but more likely it was a water droplet acting like a lens and the light hurt it.
OR even more likely I have been smoking all day long while watching our impending doom on cable news and I am too High to see