it might be unrelated to HGH use, but taken in consideration that it's most severe around where the injection areas were - is most likely caused by the HGH and most likely an allergic reaction.
indeed, in most cases the red dots are usually itchy and hot to touch BUT that's in most cases. allergic reactions are completely different and while a person gets red dots, others do not get them but get the itch. Others might not get any itch or red dots but only swells.
with this being said, there's a high chance is allergic reaction. what's strange - you got them after a month and a half. maybe that last pin wasn't well cleaned?
i guess there's no need to mention the importance of cleaning the spot very well before pinning and then wiping it after pinning. if not, dirt may be the cause of causing it.
you could try pinning it again after the red dots would disappear (they most likely would in a few days) and see how you feel.
PS: it may be an allergic reaction not to HGH itself, but to the oil used by the brand. it doesn't mean the brand you obtained is bad, it simply means that your body might not tolerate it well (we're all different!)
not sure if this helps with anything but i hope so.