I'm not really sure when the bumps come and go. It's usually just a red bump. It kinda looks like a pimple and it doesn't itch. But my scalp does feel different in the top and the crown area. Like if someone touches it or pulls on it kinda hard it hurts. Like one of my friends was curling my hair and when she got to that section my scalp felt really tender. I also noticed that I usually have a burning/sore feeling on that area of my scalp around my period. Like a few days before it and it goes away afterwards. I also shed more a few days before my period I think. I went to the doctor and told her about it. She ordered a thyroid test for me and I got tsh: 4.54 and free t4: 0.9. I took the test around 4 pm. She told me I was normal.