Always have a BBT dip day before O!?

Bryony

Hi ladies, i wonder if you can help! I’m a veteran BBT taker (ttc baby #1 for 9 months) but I always have the same pattern - bbt drop then opk positive the next day (cd13) always! I have a general thermal shift but it takes a few days after ovulation to stay up. Any thoughts ladies!!? 🙈😳 x ps you’ll also see I get light spotting on and off from about 8 to 10 dpo!