Period started, then stopped quickly

I could tell Aunt Flo was getting ready to come last week (usual PMS symptoms) , we hadn’t really tried intently this month as we are mourning a miscarriage (July 2018). TTC has been really emotionally draining since. We had sex before ovulation so it was possible, we just didn’t do it often.

Anyway, I started spotting like usual about 2-3 days ago, had some light bleeding yesterday but have had absolutely nothing today. Not even a drop. My period usually starts light, gets very heavy on day 2, then lessens and lasts about 5 days (very regular).

So of course I took a pregnancy test, it was negative. I’m confused. What else could this be? Anyone else have experience with this?