My stomach hurts REALLY bad please help?

I have a 13 year old female and i have had round worms for about 1 month now with out any treatment. Just last night i really needed to do a number 2 then i got these really strong sharp pains in my lower abdominal and bum hole too. It feels like i have been stabbed. It only started when i had constipation and i did then number 2 thinking that it would go away but it didn't go and now i am in sooooo much pain it down not hear as much when i stand up. and it is painful to touch when i have the pain but when i don't it is just sensitive. could it be the worms or an ulcers.

also i have my period right now but it i not that that is giving be the sharp pains