injection site infections anyone else had this ?

Dear all

I injected in my leg Tuesday and since then the site has been hot , inflammed , tender and painful on movement. Fortunately I had to go for bloods at the doctors on Friday so asked if I could see the practise nurse . I did she said the site was infected and prescribed anti biotics which I’m still taking .Point is leg is still as bad and wondering how long it will take for the antibiotics to kick in or whether something else is going on. Injected on thursday in stomach and no problems

Anyone had a similar experience or do you thing something else is going on?

Thanks for any replies