I am one and a half weeks late for my period and can I be pregnant and not know having taken 2 tests with one positive and one negative?

Hi there. Yes it does indeed sound like you are pregnant. You most likely got the negative pregnancy test because you did the test when there wasn't a sufficent amount of HCG in your urine or because you used a different brand of test which isn't very reliable. You need to see your doctor sweetheart for a blood test to confirm the pregnancy. You will ONLY get a positive test when HCG has been detected in your urine and HCG is only produced during pregnancy. See your doctor for a QUANTITATIVE BETA HCG blood test. This will confirm the pregnancy. Best Wishes.