App says I am in my fertile window and should ovulate in about 5days. This morning I woke to a decent amount of pink/brown discharge when wiping. Is this normal?

I’ve been off birth control since May so I am not sure what my actual cycle is- the last 2 averaged about 35 days so I’m not sure if this is an early period? My last period was 16 days ago. Or perhaps my app was incorrect during the fertile/ovulation prediction and I ovulated last week?