My periods are super irregular so not sure when my next is due. Yesterday evening I started bleeding. No before cramps, no warning, nothing. It was red and enough to fill up a pad and then a tampon. Woke up this morning and realized no blood came out over night (very unusual) and then only wore one tampon earlier today and took it out after a couple hours and it had only a little blood. Now about 4 hours later, I haven't bled anymore. This is weird for me. My periods ALWAYS last 7 days and steady flow the whole time. What could this be?