Severe cramping and blood discharge 5days/ aweek after period

Does anyone experience the same as me here?

The other day, I feel somewhat drowsy and bloating. I thought it was because I ate too much than my usual meal. So I went to bed and take nap. Next day I feel something wet on my underwear and when wiping ,it was a brown discharge spotting. It feel weird because I just finished my monthly period 5dys ago ,plus the brown discharge turn to get so red (like on the first day spotting on period) along with mucus. Feel cramping at the same time.

This is the first time I have My period twice.

Is this a serious matter or something that I should just not thinking too much?