Hello dear, I understand your concern. The calpol is the safest drug to be taken in pregnancy. It is prescribed for fever,any non specific muscle or joint pain in pregnancy. It can be taken with the prescribed dosage with no harmful effects to the fetus. But I suggest you to rule out the cause of fever and get the cause treated along with symptomatic treament. The blood counts might be need to done to rule out any infection. Also as there is leg pain any signs of cellulitis like swelling,redness etc should be checked for and I hope that was done. Once the cause is diagnosed and treated it will subside. Take adequate fluids upto 2-3 litres per day to prevent dehydration. Hope this helps. Best regards...Dr.Srilatha