A delayed period with -ve pregnancy
tests twice suggests no conception. Still, Blood HCG
testing can be done to remove the doubt.
In acse it's not pregnancy, it's menstrual irregularity,which needs investigations.
I feel you should go for Hormonal
assay & ultra sound
scan for ovarian condition. most of the times, a causative factor is clear after this. & witha Gynecologist's advice a proper management can lead to conception.