Ovulation tests is going crazy.


I bought first response OPK’s because I was running out of my healthy wiser OPK’s but I took both of them at the same time a few times in a row just so that I could see the difference between the two results. Why are they so different though? Also, yesterday I got a positive ovulation and then I got a negative and then now it’s positive again so I don’t know what’s going on.