Might be 3-4 monthes pregnant

Patient: I missed my period a few monthes back and when I took a few test it turned out negative. After that I begin to have severe stomach problems and looked up symptoms. I compared them to the beginning stages a pregnancy and it didnt add up. So I was told I could have a stomach ulcer. I looked it up and all the symptoms matched done to the foods that would upset my stomach. I couldn’t keep anything down…or even digest. I went to the doctor and since I did not have insurance the most he could do was diagnose me with acid refluxe and gave me some pills. My second and third period came but were very light. The stomach problems have mpstly subsided but my fourth did period has not come and I am noticing that I have gained some weight and my stomach has hardened. I am just now in the position to get insurance. I will take another test tomarrow but what I am worried about is if I can get all the necessary care the baby will need at this point. I heard the first ultrasound it supposed to be within the first trimester.