Could I be pregnant?

I had sex on July 3 , and have had a few early pregnancy symptoms (started about 1 1/2-2 weeks ago...tender breasts, nausea, frequent urination..etc.) I took a pregnancy test last week late afternoon, and it came out negative. My period (according to <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a>.) is suppose to come today. It did NOT come. Do you think it would be alright to test at the very end of the month, or should I test sooner?