does your baby still have lazy days?

My baby has been moving all day but she’s been quite not as active as she normally is. I’m not really that concerned because she’s been moving all day she is just not as active today as normal. I don’t kick count because it worries me but I’m sure she has moved more than 10 times today. Do they still have lazy days? She use to have them before this and the next day she was active again but I’m 31 weeks