what the heck is going on?!

My periods are usually spot on with the glow app. Usually about 6 days long with steady flow. Sorry, tmi. But my last 2 have been completely different. Both have been a few days late. But I am not sure i would really even call it a period. It's been a few spots of blood here and there for only a day or 2. Then it's completely gone. Any idea or anyone else have this going on?