Pain on the right side of the body can be a great number of problems and you will need to see a doctor for a full examination and appropriate tests.
The first thing is that pain on deep inspiration may be caused by inflammation of the lining of the lungs, however the absence of fever or respiratory symptoms reduces this possibility.
The fact that you can do a sit up with no pain implies that this is not muscle related, although cannot rule it out completely after your lunges and exercise regimen yesterday.
The fact that your bowels are normal reduces slightly the possibility of this being intestinal related, however again cannot rule it completely.
Kidney stones can present in the flank, and pain spread to the groin area although I would expect this pain to be more spasmodic in nature.
Finally the other common cause of right sided pain is liver or gall bladder related. The fact that pain is constant and worse when you take a deep breath could indicate an inflamed liver capsule.
I am sorry that I cannot be more specific however with a pain rating of 7/10 then I would suggest an emergency visit with your doctor or E.R. /A&E in order to get a full examination as soon as possible.