Is it possible for test to be positive when you are not pregnant?

I guess it is possible.. This just happen to me.. I went to the ER because I had bleeding,but thought I was pregnant even took a HPT and it came out positive.. The test I took at the ER came out negative.. They told me that sometimes when your hormones are higher than normal it can give out positive readings on HPT they checked my blood and I didn't have as high of a hormone level as most pregnant women do,but it was still pretty close. Still very confused,but oh well..