Had sex 4days ago, got urine and blood tested later on. Found little trace of blood in urine. Still having mild pain on my right side near hip bone.

Not unusual. If you have not had sexual relations for some time, a bladder infection can easily occur after intercourse. Your hip pain may also be related to a position you were in, that you had not experienced lately. Drink lots of fluid, try cranberry juice, and otc painmeds. If not better in 48-72 hours, seek medical attention.