Four days of spotting but no AF yet?

Sara

Stats- I’m 32, been TTC for about 5 months. Periods were always pretty normal, nothing screwy. Was on BC from 19-32. My luteal phase seems to be short (around 9-10 days). Anywho, ovulated on Sept 28th, BD 27th and 29th.

AF supposedly due today but hasn’t come yet. I’ve been spotting for four days with mild cramping. I normally only spot for a day and then AF shows up, and recently AF has shown up a day or two earlier than the app says it’s due. Took a HPT this morning that was negative. Any ideas?