lol !

I have had this a few times. Not sure what is actually happening but it seems like the Sus has got into my cocsix, or whatever its called - that boney tail at the base of your spine! Feels like really bad back ache! Goes after a couple of days. It may be that you injected too close to the crack of your ass also. Make sure your injecting the upper outer quadrant of your ass and it should be ok. If it continues to hurt for more that 3/4 days or gets worse then I'd go to the docs. From my experience though it will go away. Hope this helps.