It is difficult to say whether it is something urgent or not on net. You will need a doctor to feel around your abdomen and order an ultrasound or CT scan for this. If the doctor examined you and found no signs of urgency, then yes, the pain could be due to gas and mild viral gut infection due to your colds along with period pains.
If the pains persist, they have to be investigated. Pain and discomfort on the lower left side of abdomen just below and to the left of navel can be due to several causes such as Crohn’s disease, colitis, diverticulitis, infection in kidney, kidney stones, adhesions, polycystic ovary in females, IBS, constipation, and an abscess in rectus abdominis muscle or psoas muscle. Since you do not have a lump or a tender hot spot, in all probability it is not a muscle. It could also be a periumbilical hernia that has got trapped resulting in small bowel obstruction or mesenteric ischemia. There is a possibility that there is a stone in the urinary system. This also causes pain that can be felt in groin and hip area.
Do discuss this with your doctor and get yourself examined. Take care