My period returned and now it's arriving early?

Emily 🌈 • Australian, married since 2016, 2 miscarriages then my rainbow Sevana Iris was born 27th Feb 2018 💜 Tamara Aster born Sept 9th, 2019 💜

I got my first pp period at 8 months pp. It was totally normal. I started taking opks and pinpointed when I was ovulating but then my period starts at 7dpo! I'm so confused. My cycles before pregnancy were 25-28 days long. This cycle was 26, so normal but the luteal phase isn't. I'm still breastfeeding, no supplementing. Anyone been through this?