Not big,but still there is swelling around the incision(had microdiscectomy 10days ago),no pain,no redness,is that normal?

Depends: Swelling around microdiscectomy incision can be normal. If you have headaches and swelling you need to contact your surgeon as you may have a spinal fluid leak. Any redness or drainage can be signs of infection which yiu must notify yiur doctor about. If the swelling is new, then it is always best to be safe and let your surgeon know. Hope this helped.