First IUI failed... I think

Nikki

12 dpIUI, 1 day before period, and I'm getting light spotting. 2 negative pregnancy tests and 1 inconclusive. PMS is absent. Wondering what's next. I'm 37 and did natural cycle <a href="https://glowing.com/glow-fertility-program">IUI</a>. I think I'm not pregnant so do another <a href="https://glowing.com/glow-fertility-program">IUI</a> with medication or go to <a href="https://glowing.com/glow-fertility-program">IVF</a>?