After 7 months of therapy, I had my first estrogen shot on Saturday morning.

Day 0:
  After the shot, I felt cold, kind of calm and really tired.
  Probably just the tension  and anxiety going away.
  Back home, I slept the whole afternoon.

Day 1:
  Still feel really tired and cold.
  Spent an hour video chatting with my wife whom is in HongKong for a
  couple of months.
  Asked me if I was wearing any make-up. I didn't...
  Check in the mirror and found that my pores are already closing and my
  eyes where more opened.
  Don't look like a sad puppy much.
  Anxiety came back but learned to control it.

Day 2:
  My nipples are pointy and I feel like someone pinching them.
  I still feel calm but tired and really thirsty.
  It's already Monday in Japan. I'll try not sleep at the job...

I guess that 48h hours after the shot is too fast to see any physical effect.
I wonder if there isn't a placebo effect...

Many of us see the immediate physical effect of relaxing, being happy, and smiling.  That alone can erase so much of the stress and unhappiness that causes people to look, well, stressed and unhappy.

Two days for actual physical changes that you'd notice - like in terms of eyes looking wider, boobs growing?  I doubt it, although it took about one week on low dose HRT for my boobs to start hurting and feeling hard under the nipple.  I guess it wouldn't be impossible for changes to have occurred very quickly for you if you're on regular dose.

Hi Brenda!

I also doubt about having any physical effect that fast.
My mind is playing tricks with me...
I don't know the dosage (even not allowed to talk about it :-)
The shots are done at the gender clinic.
I have no control.

The changes will start coming, don't you worry about that! 

Hugs, Devlyn