Is this normal?

Okay so, I took an ovulation test on the 17th and it came back negative.. Skipped the 18th, tested again on the 19 and I was at peak... Took a test every day last week and it said I was at peak, then skipped yesterday, took another one today, and I'm still at peak... Is this normal? The ovulation tests I'm using are clear blue  advanced digital. BUT, I am also taking Feritilty Blend... Could that be giving me a faulse peak test? Or make it to where I would still be at peak? It's been over a week now.... Aren't women only at peak for 24-48 hours? Just not sure what to make of it.. This is the first month that I've really consistsly used the ovulation tests, the last few months I would use them here and there but always got a negative result... So yeah, really don't know what to think... Am I just crazy and this is nothing to worry about? Thanks so much for everyone's replies :) have a great day! :)