period is 2 days late but test said BFN

Anyone have this happen? 4 month ttc and usually I have spotting a few days before my period and can just tell it's about to come but this time nothing! I took the first response test, but it was a negative. Wondering if I should I take another in a few days? I looked online to see if tests can sometimes be wrong but it was mixed answers. Anyways I even thought that I felt really naseaus the last two weeks; or maybe it's all in my head. Sigh..