I got this little lamp at the very end of my last cycle since i didnt run a AI/SERM but the sorness went away as soon as i started letro.

Im on wk 7 of 75mg prop/tren ED. Ive been running 0.5mg letro ED since before cycle and now the lump is sore. How will I know what to run letro at next cycle of this is happening now?

Could my letro be bad?