What Cycle day do you normally ovulate?

Jaden β€’ Forever missing our Angel baby. Blessed with two earth angels!πŸ’™πŸ’—πŸ‘ΌπŸ½
I took my first ovulation test last night, CD 12 and got a negative, but had a faint line. Took another this morning and the line was way less visible. Is the line suppose to get darker the closer I am to O day?! Why is it more faint today?Β