a little help pls ladies 😘

so my fiance and I have been TTC for 2 months and my AF was due today 12/16 but showed up on 12/14. I've had what seemed to be a normal(ish) flow with no cramps at all. 12/15 and 12/16 I've had spotting 2-3 each day. This morning while working (after I ate breakfast) I got slightly nauseous and then after my lunch I developed a head ache (I work retail so it's inevitable but rarely happens to me). Now I know a period can be 3 days and I also know implantation bleeding can be mistaken for a period. do I continue on about my business like normal or take a test?