I had last sex in Oct and I had birth control tablet also then from Nov to Feb I got my period 3 times (3 times in 4 mont). Then from march to June I didn't get my period. My last period date is 12 Feb. I consulted with doctor also she told its just hormone problem.
But still I'm in confuse that I'm pregnant or is their chances that I could be pregnant or its my irregular period problem.

If you last had sex in OCTOBER then you would be around EIGHT month pregnant and due to drop at any time.
I guess you'd notice that.

Also the fact you have been having a cycle, no matter how irregular, kind of confirms things.
While not impossible it's high UNlikely you'd continue to have a period if you where pregnant.

If I got my period 3 times after last sex is there any chances that I can be pregnant?

If after last sex got my period 3 times and after that I'm not getting my period so is it I am pregnant or its irregular period problem??

I want to know exactly how many times of period will give confirmation that there is no chance of getting pregnant??

Thanks in advance.

The first symptom of pregnancy is a missed period. Since you've had 3 periods since you last had sex, AND your pregnancy test was negative, I would tend to believe your doctor.