Suggest Treatment For Soft Spot On Left Side Of Head After Injury

My 7 month old fell out of a bumbo chair onto the kitchen counter and then the tile floor, I was right there at the washer and dryer which is in my kitchen, but the folding door was open so I did not see the fall or how she landed, I only heard it. I immediately picked her up to comfort her. She was crying. Once I calmed her down I doubled checked her head but I found nothing, not even a lump. I kept a close eye on her for days afterward. However, 9 days later, I have found a large soft spot on the left side of her head and touching it lightly feels squishy. Should I be worried? Should I take her to her pediatrician or the hospital?