Positive opk for the past week?

I recently had a miscarriage (My hcg levels have been at 0 for the past week so I know the tests aren’t yielding off of hcg). I haven’t started my period yet but I’ve been taking opk tests trying to see where I’m at & for the past week they’ve all been extremely positive. Anyone know why? Im waiting on my OvuSense to arrive so I can start temping.