Weight loss advice!!?

hi, i was just wondering if i could get an estimation on how long it will take me to lose a stone. Recently i cut out carbs and basically ate yoghurt, omlette and salad for a week and i lost 3 lbs, but i gained it back when i reintroduced carbs, so this time i am taking a different approach- if i cut out white carbs, eat plenty of vegetables and fruit, go to a (sweat inducing) aerobics cl once a week as well as going jogging once a week and to the gym once a week, how long will it take me to lose 14lbs? I know everyone's body is different so i'm just looking for an estimate- also if anyone has any weight loss tips that's be great