my period used to be a bit irregular and then it changed. it all started from november 25 2012, that was the last normal cycle i had. By december 24 i had protected sex with a condom knowing that the next day my period was scheduled to come. 25 dec. came no period, by the end of december like the 30 or 31 i felt as though it was coming but went into the bathroom and still no period. january and febuary came no period!!! during those time in between january i took a pregnancy test early one that morning it came out negative. then middle feb. i took another one and still negative. now march came in i had sex again with a condom on the 23 then the next day it came on. now this is april nothing.i didnt go to the doctor, but am sure am not pregnant! please tell me what is happening!!! looks like the only way to have my periods now is to have sex!!! it doesnt want to come on its own anymore. please any suggestions!??