5 days of positive opk test when would of I ovulated

so I have a 25 day cycle most months and I start testing for ovulation on day 8 because in the past I have ovulated on day 10 , normally it’s day 12 , I had a nearly positive on Wednesday last week then Thursday it got stronger lines they where both equal in colour , Friday was meant to be ovulation day so tested at lunch and bang positive and still in the evening. I know once you get that first positive you shouldn’t need to test again but I always do to make sure the surge has been and gone, so Saturday and Sunday I tested lunchtime and evening and still positive  I use boots ovulation test strips and they are different batches so cant be faulty, I’ve done another one just 20 minuets ago and the lines are still equal, anyone else had this problem ..