Is it normal?

Glow predicted my ovulation to be last week but today I took an ovulation test and it was damn near positive..now usually my ovulation happens before glow predicts it to be so I thought it was odd. Can your ovulation days change? Or be later than expected? My period isn’t due till the 19th.. just wondering because I didn’t get to have sex during the glow predicted ovulation week but I did today so I’m seeing if I could still have a chance