Never a bad idea to get it checked out. Try that stretch I mentioned however:
go into kneeling put 1 leg foward. Put hand on hip of kneeling leg and push forward into that front leg whilst leaning backwards feeling the stretch in the front of your hip. Hold that stretch and push hard for a few seconds then release, do it 10 times.
So basically your rocking forward onto that leg and then rocking back. Do it for both legs and dig in doing it every 2 hours. after 4-5 days see if you'v made huge improvement.
If you find your Range of motion increases and your back pain decreases as well then you can avoid visiting the physio