What Causes Painful Ribcage Movement With Dizziness?

For the past few weeks Ive had movment inside my rib cage. Only along the side and in the back of BOTH sides, it is very discomforting and it feels like baby movement. I thought that I was pregnant - This is completely outruled. I have been getting my periods reguralry and still I went and got 4 blood tests done all came back Negative, 6 home Pregnancy test All negative, and an ultrasound today confirming I am NOT PREGNANT. Other stange symptoms are that Ive been dizzy a lot, and I have been feeling a little sick, but no vomiting. I have lost my appetite as well.

Im 29, 5'4, 130lbs I eat healthy food. I recently quit smoking. I exercise 4-5 times a week. Im very active since I have two chilren (ages 1 and 3)

What is this movement? Its starting to get painful as well.

Please help - any explanation as to what this could be I would greatly appreciate it!

Thank you :)