If even at 16 years of age you haven't experienced menarche, then you need to be investigated for possible hormonal, ovarian, uterine, pituitary causes for delayed menarche.
It is important that you visit your physician for a hormonal profile including FSH, LH, Prolactin, testrosterone, estrogen, DHEAS levels along with an ultrasound pelvis to rule out any mullerian anomalies or any outlet obstructions.
It is unlikely that any pregnancy would occur if the menarche has not occurred and ovulation is confirmed. The initial cycles for 1-2 years after menarche are anovulatory. so, it further reinstates that pregnancy is not a possibility in your case. Please visit your physician for a complete evaluation.
I hope i have been able to answer your query,
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