Are you sure they are posative? eg test line must be as dark as, or even darker than the control line. 2 lines is irrelevant, its how dark the line is that counts.
Could you actually be pregnant now?
Opk will show posative results when at the of the 2ww if pregnant. That was one of the things i did, i watched my hpt and opk get darker at the same time once i confirmed i was pregnant
If its not any of those do you have poly cystic ovary syndrome? in some people it can cause them to have posative results frequently.
Failing that id go see a doctor and get a blood test to see whats going on.