How long does it take amitriptyline to get outta your system if i was only taking 50mg once a day for sleep?

Less than a week: It takes 1-2 days for amitryptyline and its byproducts to drop to half the starting level. Over 95% is out by 5-10 days.

About 4 to 5 days: The half-life of Amitriptyline is from 9 to 27 hours. Assuming the higher number, after one day, there's about 50% left, after two days 25%, after three 12.5% and so on. By the fourth or fifth day, levels would be negligible.