I'm 22 & my period is a week late. I took a home pregnancy test & it came back negative. My boyfriend & I have been having a lot of unprotected sex. Could the test have been wrong?

Yes, a false negative is common, were you using the very first urine of the morning ? That is the most common error, plus at times testing too early. While a week late may show up, also just being a week late is also not uncommon either. So you may still have your period also.

I would wait one more week, and do a new test using first urine of the morning.

Yes, absolutely. Some women never test positive on a pregnancy test. It could be a variety of factors ranging from a faulty test to operator error (wrong timing, incorrect usage, etc) Try taking another test using first morning urine. If it still comes back negative. And your period is late for another week, then contact your doctor for a quantitative blood test. If they determine you are not pregnant, they can give you ideas as to why your period is late.

First of all... are you usually regular? If so you may be but I would wait a week or two to test again. If you are a false negative could be caused by taking the test wrong or not having enough hCG (pregnancy hormone) yet because its too early in your pregnancy. I am kind of in the same boat only I haven't had a period in 2 months. If you think there is a good chance you are you can go and get a blood test at your doctor or local health center. They have an almost 100% accuracy rate. There are few people who have false negatives on both, but it has happened from what I have read. I have to go in for an ultrasound to see if I am or not.