Age 31 irritated in private area, have seen change in mucus amount, no smell. blood tinge mucus 12th day cycle, expeled small darker tinge mucus piece?

Spotting day 12: At 31, the ovary is stimulated to produce more estrogen by the pituitary , and ovulation may come earlier than "day 14", with a drop in estrogen which causes spotting, just like when one misses an active birth control pill. See your gyn if this continues next cycle, and see if oral bc might be a solution, if no contraindications exist.