K.L.
It's too soon for a pregnancy test. It's even a little too soon for implantation bleeding, though anything is possible with how complicated our systems are. :) Depending on your cycle, you COULD have been ovulating on the 26th/27th. Typical a woman ovulates 14 days before her expected period. Do you chart your cycle? Perhaps start doing that, and see if this becomes a pattern. Just a thought. I have a lot of experience with cycle tracking, as I struggled to conceive for almost 3 years. Best wishes to you! If your cycle doesn't come on the 5th, TAKE A TEST!!! :)