the same day before your next test injection, the day before is fine too.
for follow up blood work I'd suggest this (copied from Kel's thread
Finding a Physician)
• Total Testosterone
• Bioavailable Testosterone
• Free Testosterone (if Bioavailable T is still unavailable)
• Estradiol (specify “sensitive” assay for males)
• LH
• FSH
• CBC
• Comprehensive Metabolic Panel
• Lipid Profile
• PSA (for those over 40 with Family Hx of prostate CA, >45 yo. all others)
• IGF-1, IGFBP-3 (if GH Therapy has been initiated already)