Kneecap pain

Hi Everyone,

New runner here and training for my first half! Usually during the middle of my long run I get mild knee cap pain/tightening that resolves pretty quickly. I’m finding my knee caps are almost creaky/painful the day after my long run but then the pain goes away about two days after. I have no issues on my shorter runs (4 miles, etc.). Any ideas/tips to preventing this or alleviating the pain?

Thank you!!