Hi, and thanks for your medical question on eHealth forum!
There are various causes for left lower abdominal pain. These are Crohnâs disease, 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. It can also be an ovarian cyst.
Yes, even a coil can cause inflammation in the fallopian tubes or can get displaced and cause similar pain.
Since a confirmed diagnosis cannot be given on net please consult your PCP to rule out these causes. Also check the thread of your implant and see if you can feel it. Get an ultrasound to see if it in place. Consult a gynecologist too. . Hope this helps. Take care!