Is it normal to have fluid moving after arm lipo? Please help. I'm so scared that I have a seroma or anything wrong

What you are experiencing may be completely normal. However as a seroma is a potential complication this should be demonstrated to your own surgeon.

Thank you for submitting your question. You need to be
examined by your surgeon to make sure you do not have a fluid collection.
In general, swelling after liposuction will last for many weeks after surgery
Final results take 6-12 months. Lymphatic massage and using a contour garment
will help with the swelling. Discuss your concerns with your Plastic Surgeon.