What are earlier signs of leukemia?

Depends: Asymptomatic lab abnormality to highly symptomatic. It depends on type of leukemia (all, aml, cll, cml, etc), disease burden, and host (human) factors. So, no universal answer.

May be few: There may be no symptoms especially with chronic leukemias. Symptoms can include fatigue, easy bruising or bleeding, shortness of breath, fevers, infections and night sweats.

Multiple: Leukemia can present with multiple signs and symptoms including but not limited to: bone pain, refusal to bear weight, gum bleeding, bleeding from other sites, pallor, lack of appetite, fever, night sweats, unexplained weight loss, easy bruising, fatigue, etc. If a concern for leukemia exists, consultation with the primary care physician or a hematologist is recommended.