Hi,
Delayed periods and fluttering sensations in the abdomen can be signs of 
pregnancy, but they can also be caused by other factors. It is important to see a healthcare provider for a pregnancy test and further evaluation to determine the cause of these symptoms.
It is also important to note that pregnancy symptoms can vary from person to person, and not all women experience the same symptoms. Some women may have a flat stomach throughout their pregnancy, while others may show earlier.
Irregular periods can make it difficult to determine pregnancy, so it is important to track your menstrual cycle or seek 
medical advice if you are unsure. Brownish discharge can be a sign of 
implantation bleeding, which can occur when a fertilized egg attaches to the uterine wall.
In summary, it is recommended to consult with a healthcare provider to determine the cause of delayed periods and any other symptoms you may be experiencing.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Priyanka, General & Family Physician