I had a wisdom tooth removed and now submandibular salivary gland is swollen. is this normal?

Rule out infection: Most likely unrelated to the wisdom tooth extraction. Submandibular salivary glands can swell due to a damaged duct or salivary stone but the area of the duct should not be disturbed by wisdom tooth extraction. A stone is just bad luck not caused by extractions. However swelling below the tongue soon after extraction should be checked for infection and could be serious. Get it checked.

Probably not: My first question is whether it is your submandibular gland or a lymph node that is swollen because they are two different things. If it is your gland then you may have a blockage or an infection. If it is your lymph node you probably have an infection. In either case you need to see your oral surgeon and have him take a look at things to see if you need to be on antibiotics.