Welcome to the Health care magic.
Dear friend you have just came back from a trip and now you have developed soar thigh and pelvis .Pain is increasing during certain movement.
In my opinion you have developed some muscular problem could be muscular spasm. You should take some rest and some muscle relaxant
medicine. You muscle should relax in day or two with this treatment.
If you do not respond to muscle relaxant medicine, then consult some orthopedic surgeon. He will further explore more possibilities.
Hope your query is answered with your satisfaction.