Knees Hurting but Otherwise Ok

My knees hurt all day today. I've been upping my distance every week. And at first everything seemed fine. When I reach the 4 mile mark, my knees start to hurt. But it's fine. I can still go at it.

My longest run is 6 miles. I've done it twice now. And it's getting a little bit easier to run. This week, I might rachet it up to 7.5 miles. But I'll need adequate rest before I do it. Otherwise, I might just get injured.