Period is late with BFN and headache

My period is always on time, but it’s currently 2 days late. I had very light spotting a few days ago, but nothing more. This is so frustrating because I have a killer headache right now and I really want to take IBUPROFEN, but I’m worried even though my test was BFN this morning! Do you think it’s safe to say I’m not pregnant and take the medication anyway?