Wondfo OPK

Does anyone else use wondfo? I have used them for awhile, & not sure If I am getting a positive? Even the negative has 2lines. Confused. Kinda bummed out now, can't tell if it's positive or not? Was hoping this was our month. Had a mc in July, & everyone said I would get pregnant right away. Now I'm not sure if I have positive opk's???