Dosage increase?

I still have 2 weeks of 1.5mg, but already got a 4mg RX filled… anyone experience any major changes in the dosage increase? I’ve done well with 1.5mg so far, 2 weeks in 12lbs lost… nausea, but nothing awful. Only bad side effect has been insomnia. Should I go ahead and take the 4mg when I’m out of 1.5 or just hold it off and ask for another month of 1.5?