Ovulation test.


So I took an ovulation test on the 24th of August. It was positive. My husband and I had sex the 24, 25, and 26. I was told you can take a pregnancy test 10 days after a positive ovulation test and if you were pregnant it would show. I took one today and it was negative. My period is supposed to start in four days. What are the chances that I might still be pregnant????