i had my son on july 19, 2008. Started my period on Aug 25, 2008. Started nuva ring on Sept 3, 2008. Had sex on Sept 5, 2008. went to ER on Sept 13, 2008, because i was sick. They took a urine test and it came back positive, so they took a blood test which came back negative. So they did both test again the urine came back positive again and blood was negative again. The doctor said he didnt know what was causing it and to go see my OB in a couple of weeks. The next day i was back in the hospital and had to have my appendix removed. Could i be pregnant or could my birth control be messing the test up?
Birth control would not be messing the test up. Pregnancy tests (both urine and blood) test for the presence of hcg, a hormone produced during pregnancy. I've heard of people having positive urine tests and negative blood tests and turning up not pregnant. The other thing is, did you get a quantitative or a qualitative blood test? A quantitative tells you the exact amount of hcg in your blood. The average non-pregnant woman will have less than 5mIU/mL. If you have over that amount, there is a good chance you may be pregnant. A qualitative blood test gives you a yes/no answer, and typically will only say you are pregnant if you test 25 mIU/mL or higher.
Starting birth control after just having a child could be causing your nausea and sore breasts.
If you want to know for absolute sure, I would recommend you get a blood pregnancy test again. Ask for a quantitative hcg test - this will tell you the exact amount of hcg in your blood and is the most accurate test for determining pregnancy.