Wondfo OPK help?

Do wondfo opks give false positives after the time too? I took the test and got distracted and it prob been about 20 mins im so annoyed that i forgot to look. Looks basically positive to me now but i dont know if they darken up alot of you leave then to sit? I know alot of you save the tests and date them and can look back and see your positive test dates i always throw mine out. I normally ovulate late in my cycle and today is cycle day 14 so it would be earlier for me but normal for most people right? And i noticed ewcm which is why i tested in the middle of the day. If you are someone that keeps your wondfo opks after the test time please tell me your input