OPK’s while BF

Has anyone else used opk’s while nursing/still hasn’t had a PP period? Four weeks ago I got a peak smiley on a digital and figured I was finally going to start my period but never did. Here has what my opk’s have looked like the last few weeks. There’s always a second line but never positive. I have since dropped a BF feeding so figured that would push me to ovulate/get period but no such luck. Any input is appreciated:)