What Causes Abdominal Pains With Fever And Chilling After Giving Birth?

i gave birth to my first baby 10 weeks ago, had an induced, quick labor and was released the next day. i am having new severe abdominal pains that have just started this week. ive also had chills but i dont think ive had a fever just chilling / cant seem to stay warm the past few days. i am breastfeeding and had my first monthly cycle about 2 weeks ago with no obvious problems at the time. could i have an infection? my stitches seemed to heal fine, just concerned about the pain/temperature issue. i also have SLE if that might make a difference.