Hard, immobile lump on the front of head

[Noureg]

about 3 days ago while rubbing my face in the morning my finger came across this small lump, it is hard, smooth, around the size of a pea (it is smaller than the distal phalange of my small finger)  feels like bone and it is firmly stuck in place i can't move it no matter how much I push it, it is right under the border of my hairline around where my hair ends and forehead begins, I think it is has remained fairly stable in size, although my sister is telling me it shrunk a little. So far I have no other symptoms, no persisting headaches (just small ones that usually end in a few minutes) and absolutely no migraines, although sometimes I feel like I have this feeling of "pressure" in my head, but it also ends in no time, and I can usually the feeling doesn't start unless I start thinking about the lump and/or about headaches, so I chalked the feeling up to stress. Could this lump be from some sort of bone or brain cancer or could it be something less serious like a cyst ?

Some extra information, I have recently been diagnosed with stage I shoulder separation, which caused a significant lump on my shoulder, which I managed to convince myself was a bone tumor, until my doctor assured me otherwise after a shoulder X-ray (Although he failed to explain why I can see a lump on the middle of the clavicle, he just told me I'm being paranoid) I also had an MRI done about 6 months ago for a separate thing and it came in normal, my shoulder and clavicle X-ray came in normal and I had some blood samples taken for work taken about 4 months ago and they came back clean too, although I think they were only checking for STDs, drugs and the such, not cancer.