Positive pregnancy test 8 days before expected period?

Okay so I have been having symptoms of pregnancy but because I want to be pregnant so bad it could all be in my head. I decided to buy some cheap dollar store tests just to amuse myself because I knew they would be negative. The first day of my last period was June 5th and I believe I ovulated on the 20th. So this morning I took two test and they were both POSITIVE. I can't believe it and I really don't want to because I still think it is way too early to test. Is it possible to get a positive so early? Maybe I misdiagnosed my ovulation time?