3, -6, 12, 4, 20, ? whats the next number please ?

Question

i have tried a few variations on sequence possibilities but i am not getting the right answer

Answer 1

error in my answer! Lynne answer good! she got the pattern for this sequence

Answer 2

to get from 3 to -6, add (-9)

to get from -6 to 12, add (18)

to get from 12 to 4, add (-8)

to get from 4 to 20, add (16)

to get from 20 to the next one, add (-7) to get 13

to get from 13 to the next one, add (14) to get 27...