In the current scenario, you should get HPT done with a fresh early morning sample of urine if you have already missed your period. Else, you should go for the serum beta-hCG titre estimation which can definitely confirm/exclude pregnancy
. You may need a trans-vaginal sonogram if the findings are inconclusive. If pregnancy can be excluded, the possibility is that you may have some hormonal
imbalance due to your age and stress
. This will usually correct by itself, but, in future, please form some form of regular contraception
. Hope this helps.