Congratulations on your weight loss!!!
I'd really recommend choosing one scale and sticking with it. Sometimes other scales are calibrated slightly off or are plain inaccurate. Scales mess with our minds at the best of times, it's best not to throw in even more variables into the mix.
In addition, it might be best to weigh yourself at the same time however regularly you choose (every day, every three days, every week- whatever). Most people choose to weigh themselves nude first thing in the morning after going to the bathroom before eating or drinking anything. If you weigh yourself in the afternoon for example and you've eaten and drunk whatever, then you're also getting the weight of what you've recently eaten. So keep that in mind if you weigh yourself several times a day and your weight seems to be all over the place.
Definitely stick to one scale, preferrably one you have access to in the morning. How often is up to you. If you choose daily, be prepared to see fluctuations that are not necessarily a reflection of how on plan you are and are usually a reflection of water retention etc; weekly can also be a downer because you don't get to see your lowest weight over the course of the week just where you are over the course of 7 days but there's nothing wrong with that. In my own journey, I started off a weekly weigher, then I joined challenges and became bi-weekly, then I became a daily weigher, and now I weigh as the spirit moves me usually 3 times a week or so.
Again well done on your achievements so far!!!