When can i get pregnant if my period last for 7 days and come in avg of 35 days and differ from month to another , today is the last day of my period?

Unclear question: Pregnancy is known to have occurred from having sex on any day of the cycle. If you wish to get pregnant, try timing sex to 14-17 days before the likely onset of the next period.

Oligo/Anovulation: If your cycles are every 35 days, you ovulate ~ day 21 and should try around that time, if you have irregular periods or want to time things more consistently, then taking Clomid (clomiphene) or Femara may be the easiest way to get you to ovulate more consistently. You should talk to your doctor about these medications to see which is best for you.