Pain upper left near ribs. Fluttery on right near ribs. Nausea. Sensitive breasts. Pelvic discomfort/pain. Dark areas on areola. Negp 10 days ago?

More details needed. Can you repeat the pregnancy test again?
Hormonal problems. Need more history, tudors producing hormones, ovarian masses, cysts, etc.
Too numerous to name. This can be so many things that it warrants a work up by a doc. In the mean time, take otc Prilosec to help make sure it's not acid reflux.
Need more info. Is pregnancy possible? What are you using for contraception? 10 days ago could have been too early for a pregnancy test to be positive yet. What are you using for contraception? There is always a concern about a possible tubal pregnancy. You also could have been exposed to hormones in something. I would advise you to see your doctor for an exam.