Why such a short period????

Dani

So i always have a normall 4 daynif not 5 day period this is how it normally works

Day 1 ....light

Day 2 heavy

Day 3 heavy/medium

Day 4 light if not spotting

Day 5 left over spitting sometimes

But ive woke up today on cd3 after putting a fresh pad on before bed and i there is nothing on it atall! And when i wiped it was like i was finishing

This is very unusual for me is this normal to have a time when your period is shorted then normal?????