I had my last periods on 13-1-2017 to 16-1-2017.. on 17th of January we had unprotected sex I am having regular backache, waistpain, pain in my abdominal area, near chest and in my legs sometimes... we had a home pregnancy test (29-1-2017) that was negative .am I pregnant or is there any chance of getting pregnant?

Pregnancy can be a possibility, but a bit early to tell with a home pregnancy test. See what happens when you would expect your next period.