You would normally be notified if it is rejected but at times, some MSC just might keep quiet until you ask. If it remained unpaid but no word from them, time to ask.
I had on one occasion wondered about a shop which remained unpaid for a while and I inquired. And that was after more than 4 months. I was told they felt I asked more than I was supposed to because the associate provided more info. I remembered that shop very well because the associate was the manager and he was covering all avenues. I stupidly included everything he said. So, lesson learned. I never volunteered any information ever again.
But on another occasion, the shop stayed unpaid and I asked. Within that week, I received the payment, without any word from the MSC. Keep you records current all the time. As long as you followed the Guidelines, there is no reason to be too anxious about your shops. Health is wealth. The MSCs are as determined as we are to have successful shops Of course, payments are another story.