Okay so maybe I'm just completely weird, but has anyone else experienced this? 

So my 1st shot was in my left leg (done by the doctor) and it was bruised and tender for a few days.

2nd shot was my right leg (done by me) and 10 minutes later I couldn't feel anything (tenderness whatnot)

3rd shot was my left leg again (done by me) and it's still tender.

Why does one leg "hurt" and the other doesn't? 

hmm I cant answer that, however I have experience somethimes where it hurts pretty much for a longer time, and other times where I nearly cant feel it.

Same thing happens to me, sorta. I don't get a bruise, or tenderness, but for some reason whenever I inject in my right leg, it inevitably gets itchy afterwards, or it hurts when I'm inserting the needle. Never a problem with my left leg.

I'm not sure, but after continually getting super sore leg when I did shots in my right thigh I stopped and only do them in my left thigh. 

On the other hand when I was getting shots done by nurses for a few months (I went through a severe anxiety period about self injecting) I noticed getting a shot in the left hip hurt me longer and more than getting a shot in the right hip. 

Okay, so at least I'm not the only one, haha. 

Hey Paul--I did my first couple shots in my thigh and it killed. Since switching to injecting in my butt cheek, I've had no pain (it also helps to have a shower first; your skin gets softer & the needle goes in easier).

Its funny-I've noticed that with tattoos; all the tattoos I have on the left side of my body hurt more than those on my right. Even my chest--the whole thing done by one person in 2 sittings, my left side killed while my right side was like, yeah its cool 🙂