Staying on same measurement/plateau

Good day everyone,I'm having a problem where I stays on same measurement and weight for 3 weeks and I have been trying multiple changes but still its same.First week,I tried to increase my workout but still no result so the later week I tried to lower my calories little and its still same.Last week I tried to lower my workout because I thought over training might be the reason but its still same again.My sleep and water intake are good so I don't know what else causing this.Should I need to change my workout routine or anything else?

Trying something different each week is not the answer, change takes time, there are no instant result in weight loss. Without more information it is impossible to know where to begin with helping you.