Positive LH results for days after trigger shot?

Hi all! Trigger shot Tuesday morning at 7am, and within 12 hours had a positive LH test. <a href="https://glowing.com/glow-fertility-program">IUI</a> Wednesday morning at 9am, followed by BD at 1am Thursday. Its now Thursday morning, and the LH is still positive?! How long does the trigger shot last? And how do I know if I have definitely ovulated? Help!