I didn't think to ask if I can take it off to sleep, or if I have to keep it on? I've had it since Friday and I took it off to sleep.

Based on the advice given by the pharmacist, it is recommended to consult your doctor or physiotherapist to determine whether you should wear the brace during the day and remove it at night for sleeping. The duration of wearing the brace will depend on the type and severity of your injury, so it is best to seek professional guidance for an accurate answer.