I had unprotected sex on 1st march and my period ended on 24th took emergency pill within 1 hr is there any chance of pregnancy?

Unlikely: If you took within an hour you should be OK but the only thing that is 100% effective is abstinence.

Very unlikely.: If taken within 24 hours of unprotected sex, emergency contraception is 95% effective. Also, since you may not have yet been in your fertile time when you had intercourse, the chances of pregnancy are even smaller. I recommend you take this as a "wake up call" that you need a reliable form of contraception. I'm sure one will be right for you.