Assalamualaikum

Wa'alaikumsalam sis! At 28 weeks tu memang normal rasa tired and achy because your body is carrying extra weight and hormones are doing a lot, lepas tu pelvis, back, legs semua stretched tu kan. Tapi kalau sakit badan tu pasal contraction-like or kalau disertai fever, better check dengan doctor cepat2 la, just to be safe. A few of my mum friends had similar feelings at that stage dan biasanya improve dengan rest, prenatal massage, or gentle stretching, tapi sebab it's quite uncomfortable for you, might be worth a quick call to your clinic okay? Take care of yourself!