Hi welcome to Health care magic forum. IUD was put 2 days back, first it was cramping, now it is not there but stomach is paining unbearable some times when you lift some thing etc. Occasionally it may be present for few days, but if it continue for 2 more days you should immediately consult your doctor. It may be the begening of the infection also.Try to avoid hard work, lifting weights, pushing some thing hard etc.
Besides i advise you some diet recommendations as avoid taking more of spices, chillies, junk foods, and oily foods. Also avoid pulses, sprouts, tubers, and fish.
Take more of green leafy vegetables, milk, egg, meat, chicken, sea foods other than fish, fruits, juices, and dry fruits, which improve blood, general health, resistance, and stamina to withstand such situations. wishing for a quick recovery and thanks for calling.