Should I Be Concerned About Whether Or Not I Am

Should I be concerned about whether or not I am pregnant. I use the period tracker app and unfortunately, I had sexual intercourse without using any protection and I have I am not using any kind of birth control and the days I had sex on the period tracker app it says I was fertile and on the last day of me having sex it says that was the day of me ovulating. And I know for sure that my partner did not pull out each time

My symptoms are nausea, dizziness, vomiting and I am not able to keep anything down and if I do eat I am feeling very sick. all the signs are leading towards me being pregnant but I know that its to soon to tell because I haven't missed my period yet its not suppose to come on until sunday 04/26/15 and I took a pregnancy test today and it came back negative