Can somebosy please help me

I don't understand why I'm having stomach pains . me and my boyfriend haven't had sex since the 25th of July I am on birth control and we didnt use protection but he pulled out my period is expect in 4 days but since I took a plan b earlier on in the month I don't know when I should expect it but I will keep u guys updated . first this morning I was having the hungry urge I was feeling real weak so I ate but I'm still hungry and now I'm having cramps my stomach feels real tight and full but idk whats going on