Fernenting Question

I made my first brew on Sunday, it is an American wheat that has been fermenting at 73°. There are still bubbles in the air lock, so it seems things are going as planned. My question is, how often should I be taking samples for testing with the hydrometer? The lid burst off the bucket Sunday night, but it has been on ever since. I'm just trying to determine when I should check it to know it is done fermenting. I plan on kegging and force carbing when fermenting is complete.

I give all my brews at least a week in primary before I even think about taking a sample. In reality, your brew will likely be done fermenting within 4 or 5 days, but a week is a safe minimum. Maybe take readings on days 6 and 7 if you're impatient, and if the grav looks good and is stable for a couple of days, you're good to go. Enjoy your first brew!