Feel the symptom but not pregnant

So I been trying to get pregnant since February and it hasn't happen yet. But for the last couple of weeks I have been feeling sick to my stomach like I'm gonna vomit but it don't happen, but eat like crazy and moody but took pregnancy test and its negative. I didn't feel any symptom with my first child but I knew I was pregnant by mother instincts I guess but I don't knw what going with my body this time should I wait and take another one next week or just go straight to the doctors