First injection, Did i do it wrong?

Hi, so I did my first injection on the 7th and don't think it's working. I was previously on patches and I had nipple tenderness every day and since switching they have gone back to normal which is why I'm thinking I messed up the injection. am I being paranoid or do you think it's possible I just didn't do it right? I've had no other changes, my mood is fine, etc, I do have a sore throat which is probably unrelated.