Help please to understand these tests

Jessica

Hi all this month I didn’t check to see when I am ovulating with anything but an OPK. I usually ovulate 16-17 CD with a 31 day cycle. Today I’m 24 CD and 6DPO. I had really sore boobs just now and thought I’d just test because I don’t usually get them. I tested on a first response early and it was positive within a minute. Tested on a digital and it says positive 2-3 weeks. Just wondering how? So happy because I’ve had 3 ectopics and 2 m/c but very confused.