Yes, CONCEPTUSES is a Scrabble word!

Letter values in Scrabble US: C 3, O 1, N 1, C 3, E 1, P 3, T 1, U 1, S 1, E 1, S 1.

Is it a valid word?

CONCEPTUSES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

an animal organism in the early stages of growth and differentiation that in higher forms merge into fetal stages but in lower forms terminate in commencement of larval life

Also: fertilized egg.