Implantation bleeding or period early?

I’ve been doing cycle monitoring and i ovulated Oct 11. Did a trigger shot the evening of oct 9. Today i started bleeding. Not as heavy as typical cycle bleeding when my period comes but def looks like period blood color. Could it be implantation bleeding or just an early period ? In the past i always have gotten my period 15 days after an <a href="https://glowing.com/glow-fertility-program">iui</a>/ovulation. Thoughts ?