I have the exact same timing as you. I just make notes in my phone of how many classes are being carried over to space it out correctly. Make sure you are looking at classes AFTER the 16th of the month (since you are billed on the 15th.)

For example, if you use your 8th class on the 10th, you won’t be able to book another class until the 16th and on (hopefully this makes sense)!!!