I took a pregnancy test that came out posotive and the other was negative, am i pregnant my nipples also have gotten bigger.?

You need blood test: Urine pregnancy tests are inconsistent early in the pregnancy. I would recommend a blood test (serum beta HCG level) to confirm or rule out pregnancy.

Blood test for HCG: If you had sex since your last period and missed your period by 4-5 days, do a home pregnancy test. If the result is negative repeat the test 4-5 days later unless you get a period by then. Use first morning urine and follow the instructions for the test carefully. If you do not wish to be pregnant, use contraception all the time, every time. You may consider implanted contraceptive, or IUD.