I don’t know when I ovulate!?!?

So my period is semi regular, I guess? I have a period every month... my cycle is 27-34 days. The problem is, I never know when I ovulate. I’ve used the ovulation test strips and I never get two strong lines. According to glow today is my ovulation day, day 15, but when I took an ovulation test it said I wasn’t ovulating. So either I missed my window or I’m too early? This is confusing to me and I’m kind of new to this. Help, please!