Wheres my oil gone?!

[Jay-ZS+]

The car was making some weird sounds this morning on the way to work when I got there checked the oil just to see and it appeared empty. Anyway before leaving work I checked again and it appeared full. Drove home and rechecked it 10mins after stoppping and was empty again.

Realise that most of it will be floating around the engine but should be some in the slump all the time, definitely 10mins after stopping.

I'm thinking filter needs changing as didn't get round to it over summer so its overdue.