2,899. When a Nazir Is Rendered Unclean

Hilchos Nezirus 6:4

If a nazir is rendered unclean on the day after completing his nezirus, which is the day he would have brought his offerings in purity had he not been rendered unclean, he only nullifies 30 days. In such a case, he brings the offerings for impurity once he been purified and he shaves for impurity. He then observes nezirus for 30 days, shaves in purity and brings his offerings. If he’s rendered unclean after the blood of his offering is sprinkled on him, he doesn’t lose any of the days he observed. Rather, he just brings the rest of his purity offerings after being purified.

Hilchos Nezirus 6:5

If the nazir was rendered unclean on the next day, which is the day he could have started re-growing his hair had he shaved it after completing his nezirus, he doesn’t lose any days even if he didn’t yet shave. This is because he has fulfilled his nazirite obligations and all that that entails.