What Causes Indentation In The Hip Muscle?

I’m 33 years old, female. I’m on medication for my migraine (taking sibelium and cataflam since last week).

Last Sunday, sudden strange indentation appeared on my right hip muscle and it is quite deep. One of the doctors that i visited suggested for blood test (SLE). i'm quite worried... any possibility of this indentation is due to SLE? No pain and no numbness.