Has my dog had a set back or is she playing us?

About two months we adopted a dog. She had issues staying by herself and when we would leave her we'd come back and she had messed but she never cried. After a few weeks of that she was perfectly fine. In the last few days she'll cry before we leave and 9 times out of 10 we will stay home or my mom takes her with us. But we can't take her everywhere. So when we leave her she'll cry but then she'll stop and when we come back she hadn't messed. We always leave a Kong out for her when we leave but that seems to have stopped working. Do you think she's had a set back or is she just playing us to get what she wants? Keep in mind she's a very smart doggie. If she's playing us what do we do?