Hello, Around 6-7 Hours Ago, I Experienced This Slight Pain

Hello,
Around 6-7 hours ago, I experienced this slight pain in my (inner) knee while I was walking at the mall. It went away after I stretched out my leg for a bit. When I came back home, I kind of tried walking around and stretching my leg to see if the "pain" is still there. Apparently, the pain is still present, but it's not that severe(?). As long as i'm walking, the pain would sometimes come back, and i would have to wait for a few seconds to continue walking. I'm a bit cautious when it comes to things like this, so i'd often consider going to a clinic or a hospital for a check up...even if it's not something serious. I'm really not the type of person who would ignore things like this, but my dad does. On another note, my dad is also experiencing back pain. He is having troubles standing up, and bending down to pick things up. I already told him to go for a check up, but he's so hard headed. Unlike me, my dad would prefer to just ignore the pain until it goes away. So, i'm here to confirm if both of us should go for a check up. I also know that it's important to have annual check ups, but we never really do that. I'll be waiting for a reply, Thank you in advance!