A day after my E shot, the area gets really sore.

I just noticed that my upper arm is quite red and tender. Not a bruise. Kind of warm to the touch like a sunburn. It extends several inches past the location of the shot.

Is this par for the course? I expect the pain to reduce by tomorrow, but I still plan on calling my doc.

Upper arm probably isn't the best place to jab a 23-25 gauge needle. Just saying (it's why the recommended areas are buttocks or legs since more muscle there)

I tried the butt, however the pain there disturbed my sleep and sitting. It is a LONG needle. I see your point about the arm.

 did you get any professional medical advise on how or where you should do it?

In the butt should not hurt if you are doing it right.

My doctor administers the shot. I didn't like the shot in the butt for the reasons listed above. He suggested the arm because he thinks thigh is the most painful.

Anyway, the redness and pain have reduced a good bit over the last few hours.

I've been doing my own injections in the thigh for more than seven months and haven't had problems.  You should discuss this more with the doctor because a rash at the injection site may be an allergic reaction to the peanut oil in the Estradiol suspension mix.  They may make other mixes for people with a nut allergy, so you probably want to do some research. 
K

Much less red on my arm today. Doc said it is not exactly a problem yet. It is not growing. Good. Call if it does grow.

I suspect I have an alergy to the oil used. I think I am his first.

I will/can take another shot... One more time... But we will need a check up scheduled. Half a week later.

That talk with your doctor was great.  Good luck with the new injection mix.

I think the best is get the shot on the butt I know that is not pretty but. is painless

It sounds like an allergy but I don't know anything about those. However, I used to get a sore thigh everytime the day after my injection (T not E so not really the same, but I thought it might be useful anyway) and I got it to stop by massaging the whole area (gently) right after the injection. Apparently it is sometimes recommended so that the hormones circulate through your body better, while others say it should be avoided, so maybe ask your doctor/make your own opinion. But it helped a lot for me, I haven't had any soreness or pain problems since I started doing this (and I'm still injecting in the thighs).

Good luck