Spotting 4 days before period

Yesterday I started spotting and I was a little thrown off because my period isn't suppose to start for another 4 days. I'm pretty regular. I might start a day late here or there but never early. By then when I went to the bathroom again it had stopped completely. I took a pregnancy test on Friday and it was a clear negative but now I'm wondering if it was just too soon to take the test. What do you think?