Stomach pains

hmg90

I'm trying to eat low carb now and getting most of my energy from protein and healthy fats. I'm eating 1300 calories a day.
Female, 23, 5"9 and slightly under 150 lbs.

I've getting bad stomach aches, now my stomach feels a bit like it does right before my period, except I'm two weeks away.
I've heard of 'keto' but I don't think my carbohydrates are that low, besides the general symptoms of fatigue etc.

Anyone else had discomfort when dieting, especially going low carb? My digestion seems to be not all right, even though I do eat vegetables every day.