When to get labs

[Youthful55guy]

I recently started TRT, test-c every 3.5 days. I inject Monday in the evening and Friday in the morning. I have my follow up six week appointment with my Dr next week and am suppose to get blood drawn for lab work this week. If I'm following the above injection schedule, should I get blood drawn tomorrow (Wednesday) or Thursday the day before my next injection? Thanks

Immediately prior to your scheduled next scheduled injection. That is, at the lowest part of the 3.5 day cycle.