Pneumo jab Prevenar - what should I expect?

[Monkeybar]

DS is having his pneumo jab on Monday and I think I'd heard somewhere that it's really nasty, hurts / stings when it's being given and gives the lo all sorts of side effects (temperature, general unwellness etc). I know why he's having it and I know he should have it, but I just want to prepare myself for what to expect.
I reckon I'll give him some calpol beforehand anyway, but anything else I need to know, please?

Dd had a very sore leg and was limping the next day. Gave her a slug of neurofen and she was OK to go to soft play later that day. No other problems. She cried as much as at the MMR when she got it but settled fast.

Every child is different.I have heard about some children having bad reactions too but my son had his pneumo jab and mmr together and was totally fine.

DD had it in the upper arm and no side effects whatsoever.

Mine had a bit of a red mark on his leg for a few days but no other effects (that I noticed)