My last period was 18th feb and than next was also 18th march but I do not get my periods even I don't feel like period like always I when I supposed to get my periods I always have cramps, lower back pain, some times itching feel on vagina but there's nothing like that. My period cycle is 30 days and I also done home pregnancy test its negative. I always have fever and I took medicine also. Why its happening? Please suggest me to what test should I go for?