What are very very first signs of pregnancy?

Varies from person: For some the first sign is a missed period without other noticeable early changes at all. For others, you may have one or more of the following symptoms: nausea day or night, increased urinary frequency, breast tenderness, marked fatigue, mood changes, food dislikes or cravings, stronger smell sensations, constipation, bloating, mild cramping, low grade headache. Do a pregnancy test to confirm.