Opk vs BBT

I know that basal body temping is the only way to confirm ovulation... but I’m getting worried because I never have clear positive OPK strips and I test up to three times a day. It’s very close, the lines are pretty much the same colour just the tiniest bit lighter and it still always seems to be almost positive the day before FF tells me I ovulated. What I’m getting at is if FF app gives me crosshairs and says I ovulated is it safe to assume I actually am ovulating every month despite never getting a blazing positive OPK?