Since you state that you feel it is not coming from the back area (muscle etc) it is something within then as you state. But you state that it is worse when you lie down. Which then would indicate a possible pinched nerve so that way when you are lying down you are compressing this nerve, even though it may not feel like it is coming from the back area.
If there is no fever, you are able to eat and drink, no unusual bathroom habits you should be able to make an appt to be seen by your doctor. If the pain gets worse or any of the above do occur then I would go to the ER. Without a possible ultra sound/x ray it would be hard to say what is going on.
If you have the insurance and you would feel comfortable, then by all means do go to the ER and be seen. Because even if you do go to the doctors office and he orders an ultra sound it may take a day for him to get the results.
You know your body better than anyone. So since there are a few possibilities as to what it could be.. use your best judgment and listen to your body, it always tells us something.
If you go to the ER or go to the doctors, keep me posted through the PM, OK? Good luck Hun.
