Odd number of leaves

Both of my older plants of unknown bag seed are changing their number of leaves randomly (I think). Both started with 3 leaves and went up to 7 normally. But now new nodes may have the normal 7, some have 5 (after the lower one had 7), and some have 4 or 6 with one not having a "partner" across from it. Is this normal, a sign of stress, or something else?

I'm not real worried because both plants look healthy. I'm growing bag seed in Fox Farm Happy Frog under a 400 watt HPS. Just changed to 12/12 yesterday. Temps vary from 74-84.

its fine bro lol

Ok, cool. Like I said I haven't been freaking, it's been like that for awhile, but it seems like my last grown they just added the number of leaves and had no deviations.

It's just weird. I thought I had a mutant.