Okay I do not want to be pregnant. However I did have sex 5 days after my last period ended. We did use a male condom and nothing bad happened with it. Exactly 22 days later I took a pregnancy test and it was negative. It has been a few days since then and I still haven't gotten my period but I do have irregular periods so I never know when I am going to get it. The test was first response if that helps. Should I take another test to be sure? If so, then when? And will it be 100% accurate?

Sadly false negatives are very common. It can take some women months, well into their second trimester, before they get a reliable reading from a test.

The only advice I can really give you is to wait until your period is at least 2 weeks late, then test using first morning urine. If that test is negative, wait for your next period and if that's missed, test again or get a blood test. If those tests are also negative, keep testing every two weeks until you get your period, or a positive result. If 2 periods have been missed without a positive result, and without a period, it's definitely time to talk to your doctor about an ultrasound to confirm that you either are, or aren't pregnant.

Good luck.