I am 22 year old . My periods are delayed about 3 months . During this delay I also have a sex with my partner. After performing pregnancy test with home kit,is negative . But still I don't get periods.I am confused that I am pregnant or not

You are exhibiting the main symptom of pregnancy, being a missed period, have you gone to your doctor. While a missed period is usually due to pregnancy that isn't the only cause there could be another reason. Please visit your doctor and they'll be able to diagnose you.