Lump in abdomen not shown on ultrasound (endo)

[LiagibaH]

Hello all. I recently had my second surgery 5 months ago to take out a large endometrioma and burn and unstick endo. I've recently started up with symptoms again such as indigestion, feeling full, nausea and bloating. I had an ultrasound scan today and they have not found any cysts so I'm stumped as to why I have these symptoms and a prominent lump in my abdomen which is there dat and night (picture attached.) I also have regular bowel movements. I have a gyny app in 2 weeks and will probabky ask for an mri scan. I've also been asked to get blood work done for hormones. I'm just wondering if anyone has had this problem or knows why or even suggestions.