Sayang, please go see your doctor or head to the clinic/hospital today, especially with the fever and all those symptoms together, better don't take chances at 16 weeks. Perut sakit, pinggang sakit, demam sejuk panas, and numbness in the legs, these things need proper checking, bukan something to wait out at home. A few of my mum friends thought their pain was normal pregnancy stuff, tapi turned out they needed proper care. Don't worry lah, doctors see this all the time, but you need to get checked properly to make sure baby and you are okay. Take care!