Lost weight but gained some back in a week?

Jasmine

So I’ve been trying to lose weight. I’ve gained 5lbs in quarantine and I’ve decided to do something about it. So for the last 3 weeks I lost 1lbs. Which I’m not mad because I know losing weight takes time. I eat healthy and clean throughout the week. On the weekend I allow myself to eat “normal” and by normal I allow myself to eat traditional home cook meals. I still portion my food so I don’t over eat. So last week I weighed myself and that is when I reached my 1lb lost. So this morning I decided to weigh myself and noticed that I went up .5lbs. I know it’s nothing but I felt a little disappointed because I finally lost a pound. I am on my period right now so I don’t know if that can affect the scale. I also do majority weight training as a workout. I’ve been wanting to grown the booty and tone the legs. So idk if I gained any muscle in the 3 weeks. Also a bit TMI but I’ve been a bit constipated. So idk if that can also affect my scale.

Any tips for keeping the weight off. Or any tips at all?