Early Positive OPK

I’m so confused . This is our third time trying after two angel babies . So I’m comfortable tracking and taking the tests . I normally get a positive around CD18 or 19. This month it’s early . Like never in two years of trying have I got a peak this early . Any reason why my body could switch . We did an insemination on the 4th which normally would have been pre peak . Doing one more tomorrow . But feel like I missed my chance with it being so early .