hi welcome to hcm.see as ur on ur 4th day of periods so there are no chance that ur pregnant.in case of your fertility
issue you go for some blood test
like FSH,LH,PROLACTIN,CBC,TSH.RBS.AND ALSO DO SONOGRAPHY
.if ur overweight
then lose ur weight .do regular exercise and yoga.and also go for husband semen report .and concern any gynec for further treatment.you described the symptoms which may be of menstrual syndrome or may be because of pain killer medicine or may be some kind of infection either viral or bacterial so concern gynec for dysmenorrohea and fertility issue.