Should I test again??

So I took 4 88cent Walmart year 2 weeks ago and they came out negative. Then I took two FRER test one the day of my missed period and the other the next day. My question is am I out? I haven’t started my period I don’t have PCOS. I’m breastfeeding but not EBF just here and there. Today I started getting light cramps in my sides and my lower left backside started hurting. It’s just a faint backache but still bothers me. I thought maybe AF was coming but then I went and looked and nothing instead my CM was thick and egg like. So confused on what’s happening to my body lol anyone know and can help a momma out? 😊

*Pic for attention