hello to everyone!

can plz someone explain me whats going on @ hashcows? (or i am not able to calculate?)

i am mining @ HC since 23rd of december. earnings were ok, started mining with 2 280x cards.

now managed to insert 3rd (of five) cards (because i wait for the risers) on 3rd of january. now mining with three cards, ~2.1MHs.

the earnings are going continuously down! from the last 24hrs @ 2.1MHs i got today 0.00693047  ! thats senseless!