I was not tested for possible pregnancy prior to being fitted for implanted birth control. i am having symptoms of pg. could i be?

Depends: It depends on what type of fitting you mean, what type of implanted birth control, and where you are in your cycle. There usually is no fitting for Nexplanon or IUD's. They are simply inserted and if this is done while you are on your period or the week after, pregnancy is very unlikely. Your symptoms could be side effects of the birth control.