How long is an opk positive after ovulation?

Jade

It’s cd29 for me and my cycles are anywhere from 4-6 weeks long. I’ve had sore boobs and an upset stomach for a week now so this morning I took an opk and preg test Below is the opk (the preg was negative) but I don’t understand because I’m sure I ovulated about 1 1/2- 2 weeks ago as I had twinges and the usual cm then, has anyone else had this before?