What if something comes up and my availability changes, can I still drop a block?

We understand life changes. You can still drop preferred scheduled blocks, and if you drop a preferred block within 24 hours of receiving it, it will not impact your block-drop rate. 

It is important you only select times you are certain you can work.  If you accurately set your availability each week with times you are willing and able to work, you are more likely to get the blocks you want in future weeks.