Could I be pregnant?

This month my husband and I decided to start trying to get pregnant. I was pretty clueless about ovulation/fertile times so decided to purchase the Clear Blue Advanced Digital Ovulation Kit. Because I was super excited/anxious I skipped the directions and took the test which gave me a solid smiley face (peak fertility) so we had sex for 3 days straight (FEB 11-13). When I cross referenced this with a few <a href="">ovulation apps</a> I have they said I was ovulating FEB 7-13 which we did also have sex a few times then as well. I was due to get my period today Feb 23 (last period was Jan 26) and havent. My cycles vary from 24-28 days but have never been past 28 days and regardless of the cycle length I ALWAYS have the same symptoms so I know a few days before I am about to get my period. I have no symptoms other than nausea and no appetite which is very new for me. I took a pregnancy test this morning which came out negative. Is it possible that I am pregnant but because it being so early it was not detected? I think whats throwing me off is that I didnt get my period. I know I shouldnt stress about it because we just started but I cant help but be.