Placebo is the strongest drug known to mankind.
I will say, when I started HRT, I felt a difference within about 3-4 days. Now, at that time I had very, very low testosteron levels, so I wasn't going to supraphysiological levels, but rather just returning to normal. I'll also admit I was scared shitless of the whole HRT idea becuase as far as I'm concerned in my mind I'm no longer "drug free" in terms of powerlifting. I didn't want the drugs to work fast, I was strong already and there was a stupid little voice in the back of my mind telling me I was cheating.
The first effects were really psychological (and I really think this is what people are feeling when they are "kicking in" with supraphysiological doses of hormones)---it wasn't that I was physically stronger, but I mentally could focus. That translated into differences in the gym. This change in psyche also could be a source of percieved differences in appearance. Think about the ugly chick who thinks she's beautiful. Its a similar phenomena. You think you are seeing/feeling/having a difference and as a result you are and you will.
Its going to take days to weeks for you to see real changes (this includes fluid retention). Even with drugs, the body needs time to build new muscle tissue. It can't happen overnight.