Continuous negative opk's!! 😡

Ok so been taking opk's the day my period finished I got a faint second line yesturday and the day before which I know is still a negative but today I got nothing just one line. today is the first day I'm suppose to be ovulating I'm so confused I'm either getting this all wrong or the tests are cheap and crap or I'm not ovulating I was in this same situation last month aswel some one please help and reply thank u xx