If you ingest chlorine, from a pool, could it give you painful stomach ache?

I am on the swim team. And I usually end up having to get out of the pool because my stomach hurts really bad! It gets so bad im in tears. And well i do swallow a lot of chlorine water when i swim on accident so i thought i might be like allergic to the chlorine. I have never had stomach aches like these so i think it has to do with swim team. I mean it only happens when i swim...