Psssst....you know you can scrap WITHOUT it being for challenges right?
Go back and check out old ones. I know that I've been around since like september/october (like around all the time) and there have been TONS of challenges that I've wanted to do but haven't had the time. Just the other day I did one for P2D #14 which doesn't count for march, but I just loved the gallery and had to play!