Should I worry

I’ve been doing a calorie deficit for a long time now. Im 5’9 and 19, I’ve went from 170 lbs to 146. I weighed myself a week ago and I was at 145.6 lbs and I weight today and was at 146. Im used to loosing .5 a pound a week but instead gained? One of the nights this week I went over my calories which are (1660) so maybe that’s why. Idk I’m just so worried of loosing my progress