do you have any sore throat or amenorrhoea before blood loss ? after blood loss you have developed low grade fever.so there is a possibility of septic abortion.you need some hematological test like cbc,platelet count to exclude ITP(low platelet),sepsis(elevated wbc,high esr).if these results are inconclusive then consult with hematologist.

hi there, heavy blood loss during mensturation is not an uncommon cause of anemia but an isolated episode should not cause you such weakness. You need to get a thorough blood work up done to rule out any underlying cause of heavy bleeding. Get a blood smear study done by a pathologist to rule out any blood related problem. If your hemoglobin is low it will cause weakness and decreased immunity which may be the reason for your low grade fever but it will need to be investigated. You can start on iron suppliments in the meanwhile but a checkup and looking for the cause is a must. Take care