Wondfo Ovulation Test Strips

Has anyone used the Wondfo brand ovulation test strips? I've been using them for months and and have never gotten a true positive result. I obviously ovulate because I keep getting my period, but the second line on the strip never gets as read as the test line... Not even close! It's so discouraging to use them each morning and to ALWAYS get what looks like a negative result. I'd spring for the name brand testers, but they're much more expensive. I guess you get what you pay for. 😕