How often do you and your fwb do it?

I have a new fwb. We hooked up for the first time August 19th, then again on the 22nd because we just so happened to run into each other at the bar. Then on the 28th he invited me over and it was the first time I stayed the night and we had amazing morning sex. He said we should do it again. soon. I hate to admit it but I really want to see him asap...but I dont want him to get bored with me too fast. How long should I wait until I allow him to see me again? how often do you and your fwb get it on?