yes that is a seed. I barely ever find seed in high quality pot. But where i live ....a state bordering mexico...there is a lot of schwagg and seeds are very normal in that. But i have got seeds out of my dankest buds only a couple times.

5 seeds- 1/2 oz. California Chronic
2 seeds- 1/4 oz. Maple Leaf Indica
1 seed- 1/8 oz. Super Silver Haze

So go plant that muthafucka(even though it doesnt look like a growable seed) and watch it grow.

much love....nasty

OH P.S. If you pinch a seed in between your index finger and thumb and it breaks its not growable.....if it doesnt crack at all throw it in the ground

just my $0.02