feel toned but not loosing inches

ive been eating healthy and exercising for a month but im barely noticing changes. my weight seems to have gone up, im still on my period so i dont know if it's that. i dont know when water weight starts to go down. im on the third/fourth day of my period. I was 12st 4lb a few days ago, now im 12st 7lb!! I've been exercising at an intense level and not eating more than 2000 calories; like between 1500-2000. I'm not even loosing iches, I've only lost like less than half an inch around my hips. before i was 42" now im closer to 41.5. it's still terrible, i should have lost a full inch. my waist is around 31-32 inches depending on when ive drunk and eaten. i feel toned but im not loosing much weight or inches. i dont want to drop my calories too low as it makes it harder to loose weight. I exercise intensely 3 times a week, im hoping to exercise more now exams are over.