I put my orders using coinigy my exchange is bittrex, usually i do this to find out what happens with my orders in coinigy:

Open coinigy and bittrex in another tab in my browser.
put an order in coinigy
Change to bittrex, this shows a small windows to the right informing how the order is filling up.

The orders are sometimes filled incrementally, bittrex shows that, for example I sell 100 eth but one buyer buys 30 units, another 30 and another 40 bittrex shows the three purchases. Bittrex show every movement in your order.
Coinigy only shows that the order was completed when it was filled to 100% in the last buy.

Sometimes an order seems to be stuck but what happens is that 90% was sold and the remaining 10% is not completed, nobody buys it because for example it lowered the price and they are buying new cheaper orders.