Spotting but not period help

Amanda • Turning the BIG 30 in April! TTC baby #2 since November 2014. My daughter from a previous marriage was born 10/14/2007. I'm a cosmetologist and going through medical assisting program!
My period was supposed to come july 2...I had really light spotting for a day and a half June 26-27....still no period...I have taken 2 pregnancy tests...july 6 & 7....both said negative....still no period....any suggestions as to what might be going on?