Positive CB digital 6 days before AF was due

I got a positive result on a clearblue digital and AF isn't due for 6 more days. I know I ovulated as it was confirmed with OPKs and bbt. Does that sound weird to anyone else?? Clear blue doesn't advertise to be able to detect pregnancy until 4 days before a missed period.

I am definitely pregnant as I've tested positive with other tests 7 days before AF was due, but just wondering if anyone else has had a similar experience!