My march period date was 20. And April was 14
That makes my cycle lengh to be 25 days..
14 April was first day and we had sex on 19, 20,21thatis : 6,7,8th day..
And my ovulation strip showed negative results till then . But 22 it showed positive for ovulation
Phad protected sex and also took iPill (anti-pregnancy pills taken within 72 hours)

Is there any chances of getting unwanted pregnancy ?

Thanks in advance...

Yes there is always a chance.