When did I ovulate?

I'm trying to figure out when it looks like I ovulated, since my period can vary by a week. Glow is guessing my period is late just by my average cycles. My smart watch takes my bbt every night, and is guessing I didn' t ovulate until 2/24 so period isn’t due yet. Yesterday & today I've had light spotting- light pinkish brown mainly, and once a bit of dark red. Does this mean my period is coming and my bbt isn’t lining up? Or am I reading the chart wrong? Or possibly implantation bleeding? I never had implantation bleeding with my 2 pregnancies. Thanks for any help!