Significados de own nativity en inglés

I swear I will stand by my own nativity, pious or impious so be it;

I then asked him why he had not calculated his own nativity, to see whether it agreed with Bickerstaff's prediction?

I then asked him, "Why he had not calculated his own nativity, to see whether it agreed with BICKERSTAFF's Predictions?"

He constructed a scheme of his own nativity, calculated according to such rules of art as he could collect from the best astrological authors.