16dpo, 40 days cycle

Hello, i experienced irregular period everysince i was 15 but i dont bother much because im young and doesnt want to have a baby yet. I am using contraceptive pills to regulate my menses until 26 years old. This year june 14, i married my long time bf of 11years. We planned to have a baby so i took clomid starting july to september but i constantly got negative PT. I quit using clomid after my september dose.

I usually have 40 day cycle, my logest is 45 days. Today iam at 42 days and according to logs i might be at 16 days past ovulation. I am afraid to use pregnancy test because i might be disappointed again. Any suggestion when to use pregnancy test? What are the sign i need to see at 16DPO in case of pregnancy. Thank you