I'm a newbie as well, but I've seen that.
Indoor grow, right?
How old is the plant and how long have you had it on your flowering light schedule?
What is your light schedule? Anything weird happen to your plant?
I stressed, almost to death, a couple clones of mine. Damned spider mites.
Went nuclear with neem oil. At any rate when they came back to life they had leaves like yours.
Do you have time to reveg?