Best days for conceiving are days around the ovulation. Ovulation happens about 14 days before the next period comes. This means that in your case ovulation should happen on 7th May 30 - 14 days = 23th May. You should have intensive sexual intercourses starting from 21st up to 25th May.

Thanks a lot Doc.

If i have unprotected sex from 16th to say 19th May do u think i can get pregrant or is it a safe period.

You can get pregnant but chances for getting pregnant would be much greater if you have sex during the fertile days (21-15th May) of your cycle.