Signs of ovulation but the ovulation kit reads negative?

I have egg white like CM and can feel abdominal twinges but the ovulation test kit is reading a negative result for the LH surge. Has this happened to anyone else? I have a very irregular cycle to try track by a calendar so I rely on knowing my body and its hormonal changes. These ovulation kits drive me crazy and buying them multiple times can get expensive so I am thinking of not using them all together and just enjoying being intimate with my husband.