Weird period after a month help!?

i was on bc for a month and 9 days i began to get some severe stomach problems where i threw up and couldnt eat... went to the emergency room to try and figure it out. stopped the birth control and was no longer sick. my doctor said it could have been too muc estrogen. my last period was from june 9-13 stopped the bc on june 23. i took a pregnancy test and it was neg... please whats wrong with me and why havnt i had a period?!