The output states of flip-flops, registers, counters and one-shot multi-vibrators after power-on are not determinate. (They can be High or Low.)
Generally, the logic state after power-on is initially set by temporarily asserting the CLEAR pin or another pin. This is called a power-on reset. Power-on reset is performed either by a power-on reset circuit that consists of resistors and transistors or by an IC specifically designed for a reset signal.