It's not about your scale, it's about your body. A woman's body often undergoes abrupt changes that are sometimes difficult to explain. It is in such cases, I am very helped by my smart scale https://www.amazon.com/Vont-Smart-Body-Scale-Black/dp/B08XYX8RDR/, it allows me to track changes in my weight as quickly as possible. I understand that it's sad to lose weight when you've gained muscle mass. Treat it as a feature of the female body, because at the time of ovulation and menstruation in our body changes.