rotating injection sites

With a daily shot rotation, how often can the same muscle be hit? Is every 4th day too often? What's the risk of hitting the same area too often? Just scar tissue, or infection also? Thanks in advance.

I inject .25ml for a total of 50mg of test cyp Monday, Wednesday, and Friday. I did Sub Q for the first 8 weeks but every time I would get a lump the following day that would last for 2-3 days. I rotated sites all over the place and every time I would get a the lump. Decided to start IM last...