Period 12/2-12/5. i ovulated 12/13 12/14.last night 12/23 noticed brown blood not a lot is this normal red blood now i never spot like this too early?

Hormone fluctuation?: Occasional menstrual irregularities (including spotting, early or late periods and color changes) are quite common even in women with very regular cycles. If irregularities reoccur for 3 consecutive cycles, it's worth your while to consult your gyno. If you had sexual intercourse during this cycle, it's not too soon to check a home pregnancy test. Best wishes!

Spotting: sounds like some premenstrual spotting. This is relatively common and can be spontaneous or brought on by things like intercourse. Technically based on your dates this is a 21 day cycle, which is not short. However, if you normally have a longer cycle (start of one period to start of next) then it may be a short cycle for you. Check a pregnancy test in about a week in case its implantation