Irregular periods after miscarriage... short luteal phase??

I stopped BC in May, got a period in June and then got my BFP at the beginning of July. I miscarried at beginning of August. It took until until almost the end of September for my levels to drop. I got my first period on October 12, but I had 4 days of spotting before that. I thought it was probably just due to the miscarriage and didn't worry that much. But now I'm spotting again. Hardly any and very light brown. Today is CD25 and spotting started yesterday. I'm pretty sure I'm only 10DPO, but I didn't chart this month. I know how beneficial charting is and was charting when we first TTC, but I constantly wake up throughout the night, so I think it made my temps inaccurate.

Since I got pregnant after only having one period after stopping bc, I haven't really established what a "normal" period is for me. I do know that I used to never spot for several days like this. I would usually only spot for one day prior to AF and even then it was usually only 12 hours or so beforehand. I've read that spotting before 12dpo is a bad thing and a sign of a short luteal phase and/or low progesterone. Before I miscarried, I was told that my progesterone levels were "through the roof" so I don't think low progesterone was a problem then. But can a miscarriage cause hormones to be thrown off this long after? We are TTC again and I'm so scared that my hormones are all messed up, making conceiving impossible.