molly bloom
I have experience with this. Does your company own the building? If so, then you need to go to HR and say that you are having these headaches, and you would like to check for mold in your office.
If your company does not own the building, then whomever is the property management company, needs to be contacted, and ask that an inspection be made by an environmental engineer.
Once the complaint is made, then action has to be taken to mitigate whatever future health issues (usually deep pocket) can be handled. Someone may come out and try to just look at it, and maybe say "that doesn't look so bad" or "that doesn't look like mold to me". Stand firm. Keep repeating that you would prefer a report from a qualified engineer.
Two things should happen. First, there should be a thorough air quality test. Second, there should be a sampling of ceiling tiles. You need both those tests. Depending on the area, those tests will probably run about $750 per test, which is also dependent on the number of samplings.
An environmental engineer will then write up a mitigation report, and usually know contractors that are qualified to remove hazardous material.
You will not be popular, but who cares? This is your health.
If you live in the Northwest, I have a company name for you.