it is 1 of two things.

1) your light is too close as indicated by the leaves folding in on themselves. Near the left side of the picture.

2) the humidity could also be too high. Depending on the strain, ideal humidity could be high or low. Generally though humidity should be between 65-84 give or take a degree during veg state. You are in flowering and after 15 days you should see a very noticable difference in size and smell. You want lower humidity for flowering.