I want to have another child, but don''t want to go back to the doctor acting paranoid

Im 27years old. Mother to three children 6,4,2. I had unprotected sex early January about the same time my period was due. I missed my January period and am currently 4 days late for the February cycle. I am always regular, but the past few weeks I have had constant headaches, feeling sick without vomiting, vomiting, food tastes funny to me and I want to eat, but then only eat a little and feel full, Im gassy and feel bloated and my stomach feels tight all the time no matter if im laying or standing or walking around. I went to the doctor at the end of January and a urine pregnancy test came back negative. Not sure if the pregnancy would have shown up after only three weeks or if I should wait a few more weeks and see if my period turns up. I want to have another child, but don''t want to go back to the doctor acting paranoid if it turns out I was just late again. Any thoughts on if it sounds familiar? I have also lost a few kilos in the past few weeks (which I know I did when I was pregnant with my daughter aged 6)