Hello dear
Understand your concern.
Yes delay in period is most common and definitive sign of
pregnancy in sexually active women.
Urinary pregnancy kit give negative result in early stage because of low level of HCG in urine.
It give positive test only 7-10 days after missed period.
But blood HCG is very sensitive to detect pregnancy, as evel increased 7 days after ovulation/conception.
Abdominal USG is confirmatory test.
So I think you should go for Blood HCG and USG abdomen.
Also note the other causes of delayed period:
1.
Hormonal imbalance
2.
Excessive weight loss or gain
3. Excessive stress
4. Thyroid disorder
5. Endometriosis
6. PCOS
7. Prolactinoma
8. Fibroid/adenomyosis
9. Cancer or pre cancerous condition of cervix/uterus/vagina
10. perimenopausal/Menopausal sate.
11. Ectopic pregnancy
Yes you can go for test.
If negative than you should consult the gynecologist and do the following test
1. Hormonal profile: HCG, prolactin, LH,FSH, Estrogrn.
progesterone, prolactin
2. USG abdomen
3. PAP smear
4. Endometrial biopsy
5.
Ovarian follicle study . to exclude all the above causes.
Hope this may help you
Best regards
Dr. Sagar