Chillax, OP. You've broken skin with a pointy object - a small blob of blood is absolutely normal.
All mine are done by a doctor and I more often than not see a tiny bit of blood on the back of the [generic country agnostic word for sticky wound covering thing] and *strokes beard* my T appears to be working just fine

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Hell, I've even had a spurter! Got a few drops on the back of my pants and all. That was a surprise (but the doctor said "Yeah, that happens sometimes. It's unusual, but perfectly normal. It's just chance").
I've also had 2 needles fall apart. One just exploded and got the T all over the room before it was injected - needed to drive home and bring back another amp, and the other was the doctor seeing how fine a gauge we could get away with. Snap on end of needle came off right at the end of the shot from the pressure - but the T still went in prior to that so it was all good.
There's a big margin of error and lots of variables in shots. Try not to worry about it

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