I was about to get my periods on August 18th still now nothing. I took HPT one came +ve and other 2 came -ve. My Dr. called me yesterday and said I did not ovulate this month, then how come a +ve HPT. I have some symptoms of Pregnancy but not all. Please help me.

How does your doctor know you did not ovulate? Are you having some medical assistance with becoming pregnant? If so, sometimes certain fertility meds can cause a false positive.
It could also be from a faulty test, reading it incorrectly... the mistake is most often reading it after the allotted time frame, different tests with different sensitivity levels, or a pregnancy that didn't take... used to go unnoticed, but with early testing, more and more women will see this.
Certainly, if you continue to feel some symptoms... and your period still doesn't show, you may want to try another test in a week or so just to be sure it is indeed negative.