This is a common problem in your culture, As your not the only man that has been posting such problems and concerns. Is this an arranged marriage by chance?

I'm sorry that she trusted you enough to tell you to be honest, Now you are judging her unfairly.

You have a few options.... Get over it and realize she is with you and her past is not part of your present relationship, or continue to judge her unfairly and possibly make her miserable for being honest and you will always feel insecure. If you really can't move past this, end the relationship and find a virgin to marry.

I'd vote for just loving her 100% and look forward to make a wonderful life with her.

I wish you the best.