Period tricking me smh

ugh I've had my periods for 4days this is the 5th day and I hope it ends within the next hour or so. Basically I thought my period ended and I took my pad off because all day nothing happened like only in the beginning of the day so I showered and 3 hours later when I was busy and couldn't go to the restroom I found out my period never left and well my underware got dirty like wow I have no unperiodified undies left I'm mad lmao PLS how do I know when it's actually gone?