Yeah, laptops now have a single headphone & mic combo jack. When you plug in your headphone it disables the laptop built-in microphone. The way around this is to purchase a headphone set with a microphone.
Below are examples of headphones with built-in microphones that are relatively inexpensive. They represent different styles; earbuds, on the ear, and over the ear. Note, I am not endorsing any of these headphones / headsets as I do not have any experience with them. Additionally, spending more money generally means better quality components are used. Read reviews before making a purchase.