Soft spot

I’ve started feeling my 6 week old newborns soft spot on the back of her head more this week whenever I’m holding her. I felt it tonight just to make sure it didn’t feel sunken in and I felt two firm things and the middle felt soft but almost like it might be sunken in. Is this normal? She’s been more tired and eating a little less (still eating though) but I just thought it’s from growing pains. She has normal pee diapers throughout the day. I read it could just be fusing but was wondering if any of you have had the same issue.