Whyyyyy would this be happening?!

Can someone please help. I am so confused.

I just had a chemical on Feb 16th. Heavily bled for 2 days then tapered off and was lighter days 3 and 4, still spotting today (CD 5).

I took an HCG test just now to see if there would still be a hint of a line. There isnt, its stark white. But then I decided to take an opk (something was pushing me to), and its POSITIVE?! I don't understand how this would happen so soon. I find it so difficult to get a positive on an opk even when I am trying to.

I know some women say they got pregnant right after a chemical. But how soon after? Could there be another reason for this? Cervix also feels high and soft, not as open as usual but slightly open.

We are ready to try again. Just wasn't expecting this for another 10 days or so.

Anyone experienced this?