Suggest Medication For Weight Gain,breast Tenderness And Nausea

I am a 22 year old female, 5'1" and usually weigh somewhere between 110 and 114, depending on whether or not I've eating in the past four hours or so. I don't have much of a medical history. I've gone into the hospital a total of...well, what is essentially "three" times. Once after getting hit by a car in late March of 2008 for what was basically just some deep muscle pain in my hips and stomach, where I had landed and taken the brunt of my bike's weight, once when my appendix spontaneously ruptured in late January of 2009 and then again for most of 2009 when I was pregnant with my son. I consider this last to be basically "one" time, since all were linked with the pregnancy. I got pregnant about two weeks after my appendectomy, in a "Yay, I'm not dead!" celebration with my husband. It wasn't exactly a normal pregnancy. I had no symptoms except a missed period until I was about four months along, when randomly I became severely anemic. It was so bad that I couldn't stand up for longer than about five minutes without almost passing out. When I was almost in my third trimester I went into pre-term labor. They got it stopped, put me on some meds, and I continued to have constant contractions that were only prevented from getting worse by the meds. I went into pre-term labor again a couple of months later, and they got it stopped again. I wound up delivering my son about a week after his due date, and no, it wasn't an induced labor.

Anyway, as to my problems now. Right around the 16th of April I became concerned I was pregnant because my period was a couple of days late. I decided to wait a week. On the 20th of April I got my period, but it was a little lighter than normal (generally it's moderate to heavy, this time it was just barely moderate), only lasted two days instead of the usual seven, and was not accompanied by the usual severe cramps or foul odor. A day after it stopped I went in a got a pregnancy test done, thinking that it might have been decidual bleeding. The test came back negative. Since then I've been feeling an aversion to a lot of foods, though not what one would generally call nausea. I still eat well, though not quite as much as I did before. Also, I've gained a couple of pounds, and my pants seem a bit more snug than normal. No breast tenderness, although for the past couple of months my right breast has started to hurt if I sleep on my right side, but it goes away right away if I sleep on my back or on my left side. So, about yesterday/today.

Yesterday, around 1:00 pm (about three hours after I woke up...um, oh yeah, I also have delayed sleep phase disorder) I started feeling very nauseous and light headed, and I'd get very dizzy when I stood up. At about 10:00 last night I began to feel what is essentially between an ache and a sharp pain in the right side of my abdomen. Sometimes I'd feel it near the back, sometimes in the front, and it was generally just above, but always to the right of, my navel. Sometimes, it almost felt like hunger pains, but eating a sandwich didn't help. It usually get's more intense/severe if I try to use my abdominal muscles for anything, like sitting or standing up without the assistance of my arms. It is now almost noon, and I'm concerned that it might be any number of things, including an ectopic pregnancy, though it's a little bit too high for that, and the test did come back negative. I would greatly appreciate any help you can give me. Thank you.