Well based on ur description, take care of ur meals n drinks -- minimize cold food n drinks; eg. those taken out directly from fridge; ice cream; drinks with ice cubes ...   It would help a lot.

It would mean having less fun in food n drinks, but in long term, would u prefer having a better health, or keep suffering from existing condition ?  

Have u seen a doctor ?

how old r u ? if teenage no worries..its normal. ..will be ok as u become older... 

yup, agree, dun take so much cold food and drink.
cos it will make your uterus 'cold' and cannot operate well during period
well, what i mean is medically, when the ovum break down and starting to become the period blood, if your uterus 'get cold' the breaking part will be congeal(beku) and end up become the 1 piece 1 piece you meant.
better take more hot food and drink.

and 1 thing, Chinese said period is kind of 'cold' (as you know when weather hot, they always said will heaty,so this is d vice verse )
so DUN eat gui ling gou , cos this is the COLD food that help to reduce heaty. and those 'leong shui' oso better dun drink.

try to boil some drink that helps to 'restock' blood for girl
'gei zhi' (Cantonese, wolf berrie) + brown sugar (or gula melacca) with water
It help.
or take the ‘bak fong yun'(Cantonese) after period, can help to mediate:)

After give birth will be ok gua. My mom say she's lucky to have me coz after I come out she don't suffer any harsh period pain jor..