I have a silly question

Today I am 7 dpo and I been having some symptoms. Cramping, Nausea here and there, extreme fatigue, increased appetite, cravings, etc. AF is due 05/07. This is my first time using opks. I got some really dark lines when I was ovulating. After I ovulated they were barely there at times and at times not there at all. Hubby read somewhere where opks can pick up pregnancy hormones. Although I think it's to early to use my pregnancy test I did decide to try his theory on using an opk stick. After the 4 min time frame I checked it and it was a positive opk. Has anyone heard about this, Or has this happened to anyone where one wk you had positives then they disappeared and a wk later they are positive again? I know it's silly but I figured it doesn't hurt to ask :)