Always do! Check the truck tires all the time too.
Had a leaky tire, drivers side-front, on the truck. When I had an oil change done, I even had "them" check the tire, it was such an unpredictable leak. One day is with at 80 psi, the next it would be down to 40. Then it would stay at 80 for a week, and then drop over night again. They couldn't find anything wrong with the tire.
I finally took it back and said, there is definitely something going on. Check the valve stem too! They did... it was the valve stem. They replaced it $12.50.
So, while checking your tires, don't forget the valve stem also. If a tire starts dropping in pressure, splash some soapy water on the valve stem, watch for bubbles.