An infectious appendix would show elevated WBC and lymph’s on a CBC. You might try calling your GYN since your post-partum to check if they have any ideas they may have heard from other patients. I’m an old nurse with no peds training nor do I have any kids. But which side of your body are you carrying the baby on? Since you now have this new weight to carry around I’m just curious is it plays a part? Good luck with an answer.