Eh abang, at 37 weeks tu memang normal rasa sakit dan bengkak kat bekas suntikan imferon especially kalau dah 15 dos, a few of my mum friends complained about the same thing, some even tak boleh tido menyangkut sampai nak delivery. The soreness, numbness, and local swelling usually settle dalam 1-2 minggu tu, tapi since you're having your blood check hari ni, best to mention it to your doctor just to make sure everything's okay and maybe they can suggest something for the discomfort macam cold compress or gentle stretching.